WorldWideScience

Sample records for sound source radiating

  1. Sound power radiated by sources in diffuse fields

    DEFF Research Database (Denmark)

    Polack, Jean-Dominique

    2000-01-01

    Sound power radiated by sources at low frequency notoriously depends on source position. We sampled the sound field of a rectangular room at 18 microphone and 4 source positions. Average power spectra were extrapolated from the reverberant field, taking into account the frequency dependent...

  2. Sound and sound sources

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Wahlberg, Magnus

    2017-01-01

    There is no difference in principle between the infrasonic and ultrasonic sounds, which are inaudible to humans (or other animals) and the sounds that we can hear. In all cases, sound is a wave of pressure and particle oscillations propagating through an elastic medium, such as air. This chapter...... is about the physical laws that govern how animals produce sound signals and how physical principles determine the signals’ frequency content and sound level, the nature of the sound field (sound pressure versus particle vibrations) as well as directional properties of the emitted signal. Many...... of these properties are dictated by simple physical relationships between the size of the sound emitter and the wavelength of emitted sound. The wavelengths of the signals need to be sufficiently short in relation to the size of the emitter to allow for the efficient production of propagating sound pressure waves...

  3. Separation of radiated sound field components from waves scattered by a source under non-anechoic conditions

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn

    2010-01-01

    to the source. Thus the radiated free-field component is estimated simultaneously with solving the inverse problem of reconstructing the sound field near the source. The method is particularly suited to cases in which the overall contribution of reflected sound in the measurement plane is significant....

  4. OMNIDIRECTIONAL SOUND SOURCE

    DEFF Research Database (Denmark)

    1996-01-01

    A sound source comprising a loudspeaker (6) and a hollow coupler (4) with an open inlet which communicates with and is closed by the loudspeaker (6) and an open outlet, said coupler (4) comprising rigid walls which cannot respond to the sound pressures produced by the loudspeaker (6). According...

  5. Visualization of Broadband Sound Sources

    OpenAIRE

    Sukhanov Dmitry; Erzakova Nadezhda

    2016-01-01

    In this paper the method of imaging of wideband audio sources based on the 2D microphone array measurements of the sound field at the same time in all the microphones is proposed. Designed microphone array consists of 160 microphones allowing to digitize signals with a frequency of 7200 Hz. Measured signals are processed using the special algorithm that makes it possible to obtain a flat image of wideband sound sources. It is shown experimentally that the visualization is not dependent on the...

  6. Visualization of Broadband Sound Sources

    Directory of Open Access Journals (Sweden)

    Sukhanov Dmitry

    2016-01-01

    Full Text Available In this paper the method of imaging of wideband audio sources based on the 2D microphone array measurements of the sound field at the same time in all the microphones is proposed. Designed microphone array consists of 160 microphones allowing to digitize signals with a frequency of 7200 Hz. Measured signals are processed using the special algorithm that makes it possible to obtain a flat image of wideband sound sources. It is shown experimentally that the visualization is not dependent on the waveform, but determined by the bandwidth. Developed system allows to visualize sources with a resolution of up to 10 cm.

  7. Numerical simulation of aerodynamic sound radiated from a two-dimensional airfoil

    OpenAIRE

    飯田, 明由; 大田黒, 俊夫; 加藤, 千幸; Akiyoshi, Iida; Toshio, Otaguro; Chisachi, Kato; 日立機研; 日立機研; 東大生研; Mechanical Engineering Research Laboratory, Hitachi Ltd.; Mechanical Engineering Research Laboratory, Hitachi Ltd.; University of Tokyo

    2000-01-01

    An aerodynamic sound radiated from a two-dimensional airfoil has been computed with the Lighthill-Curle's theory. The predicted sound pressure level is agreement with the measured one. Distribution of vortex sound sources is also estimated based on the correlation between the unsteady vorticity fluctuations and the aerodynamic sound. The distribution of vortex sound source reveals that separated shear layers generate aerodynamic sound. This result is help to understand noise reduction method....

  8. Directional sound beam emission from a configurable compact multi-source system

    KAUST Repository

    Zhao, Jiajun; Jadhali, Rasha Al; Zhang, Likun; Wu, Ying

    2018-01-01

    We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation

  9. Material sound source localization through headphones

    Science.gov (United States)

    Dunai, Larisa; Peris-Fajarnes, Guillermo; Lengua, Ismael Lengua; Montaña, Ignacio Tortajada

    2012-09-01

    In the present paper a study of sound localization is carried out, considering two different sounds emitted from different hit materials (wood and bongo) as well as a Delta sound. The motivation of this research is to study how humans localize sounds coming from different materials, with the purpose of a future implementation of the acoustic sounds with better localization features in navigation aid systems or training audio-games suited for blind people. Wood and bongo sounds are recorded after hitting two objects made of these materials. Afterwards, they are analysed and processed. On the other hand, the Delta sound (click) is generated by using the Adobe Audition software, considering a frequency of 44.1 kHz. All sounds are analysed and convolved with previously measured non-individual Head-Related Transfer Functions both for an anechoic environment and for an environment with reverberation. The First Choice method is used in this experiment. Subjects are asked to localize the source position of the sound listened through the headphones, by using a graphic user interface. The analyses of the recorded data reveal that no significant differences are obtained either when considering the nature of the sounds (wood, bongo, Delta) or their environmental context (with or without reverberation). The localization accuracies for the anechoic sounds are: wood 90.19%, bongo 92.96% and Delta sound 89.59%, whereas for the sounds with reverberation the results are: wood 90.59%, bongo 92.63% and Delta sound 90.91%. According to these data, we can conclude that even when considering the reverberation effect, the localization accuracy does not significantly increase.

  10. Offshore dredger sounds: Source levels, sound maps, and risk assessment

    NARCIS (Netherlands)

    Jong, C.A.F. de; Ainslie, M.A.; Heinis, F.; Janmaat, J.

    2016-01-01

    The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels

  11. Directional sound radiation from substation transformers

    International Nuclear Information System (INIS)

    Maybee, N.

    2009-01-01

    This paper presented the results of a study in which acoustical measurements at two substations were analyzed to investigate the directional behaviour of typical arrays having 2 or 3 transformers. Substation transformers produce a characteristic humming sound that is caused primarily by vibration of the core at twice the frequency of the power supply. The humming noise radiates predominantly from the tank enclosing the core. The main components of the sound are harmonics of 120 Hz. Sound pressure level data were obtained for various directions and distances from the arrays, ranging from 0.5 m to over 100 m. The measured sound pressure levels of the transformer tones displayed substantial positive and negative excursions from the calculated average values for many distances and directions. The results support the concept that the directional effects are associated with constructive and destructive interference of tonal sound waves emanating from different parts of the array. Significant variations in the directional sound pattern can occur in the near field of a single transformer or an array, and the extent of the near field is significantly larger than the scale of the array. Based on typical dimensions for substation sites, the distance to the far field may be much beyond the substation boundary and beyond typical setbacks to the closest dwellings. As such, the directional sound radiation produced by transformer arrays introduces additional uncertainty in the prediction of substation sound levels at dwellings within a few hundred meters of a substation site. 4 refs., 4 figs.

  12. Binaural Processing of Multiple Sound Sources

    Science.gov (United States)

    2016-08-18

    AFRL-AFOSR-VA-TR-2016-0298 Binaural Processing of Multiple Sound Sources William Yost ARIZONA STATE UNIVERSITY 660 S MILL AVE STE 312 TEMPE, AZ 85281...18-08-2016 2. REPORT TYPE Final Performance 3. DATES COVERED (From - To) 15 Jul 2012 to 14 Jul 2016 4. TITLE AND SUBTITLE Binaural Processing of...three topics cited above are entirely within the scope of the AFOSR grant. 15. SUBJECT TERMS Binaural hearing, Sound Localization, Interaural signal

  13. Sound radiation from finite surfaces

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2013-01-01

    A method to account for the effect of finite size in acoustic power radiation problem of planar surfaces using spatial windowing is developed. Cremer and Heckl presents a very useful formula for the power radiating from a structure using the spatially Fourier transformed velocity, which combined...... with spatially windowing of a plane waves can be used to take into account the finite size. In the present paper, this is developed by means of a radiation impedance for finite surfaces, that is used instead of the radiation impedance for infinite surfaces. In this way, the spatial windowing is included...

  14. The Environmental Cost of Marine Sound Sources

    NARCIS (Netherlands)

    Ainslie, M.A.; Dekeling, R.P.A.

    2011-01-01

    Cumulative acoustic exposure is used as an indicator for the risk of negative impact to animals as a consequence of exposure to underwater sound. The free-field energy of a single source, defined as the total acoustic energy that would exist in the source’s free field, is shown to be closely related

  15. Microflown based monopole sound sources for reciprocal measurements

    NARCIS (Netherlands)

    Bree, H.E. de; Basten, T.G.H.

    2008-01-01

    Monopole sound sources (i.e. omni directional sound sources with a known volume velocity) are essential for reciprocal measurements used in vehicle interior panel noise contribution analysis. Until recently, these monopole sound sources use a sound pressure transducer sensor as a reference sensor. A

  16. Perceived loudness of spatially distributed sound sources

    DEFF Research Database (Denmark)

    Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

    2005-01-01

    psychoacoustic attributes into account. Therefore, a method for deriving loudness maps was developed in an earlier study [Song, Internoise2004, paper 271]. The present experiment investigates to which extent perceived loudness depends on the distribution of individual sound sources. Three loudspeakers were...... positioned 1.5 m from the centre of the listener’s head, one straight ahead, and two 10 degrees to the right and left, respectively. Six participants matched the loudness of either one, or two simultaneous sounds (narrow-band noises with 1-kHz, and 3.15-kHz centre frequencies) to a 2-kHz, 60-dB SPL narrow......-band noise placed in the frontal loudspeaker. The two sounds were either originating from the central speaker, or from the two offset loudspeakers. It turned out that the subjects perceived the noises to be softer when they were distributed in space. In addition, loudness was calculated from the recordings...

  17. Seismic and Biological Sources of Ambient Ocean Sound

    Science.gov (United States)

    Freeman, Simon Eric

    Sound is the most efficient radiation in the ocean. Sounds of seismic and biological origin contain information regarding the underlying processes that created them. A single hydrophone records summary time-frequency information from the volume within acoustic range. Beamforming using a hydrophone array additionally produces azimuthal estimates of sound sources. A two-dimensional array and acoustic focusing produce an unambiguous two-dimensional `image' of sources. This dissertation describes the application of these techniques in three cases. The first utilizes hydrophone arrays to investigate T-phases (water-borne seismic waves) in the Philippine Sea. Ninety T-phases were recorded over a 12-day period, implying a greater number of seismic events occur than are detected by terrestrial seismic monitoring in the region. Observation of an azimuthally migrating T-phase suggests that reverberation of such sounds from bathymetric features can occur over megameter scales. In the second case, single hydrophone recordings from coral reefs in the Line Islands archipelago reveal that local ambient reef sound is spectrally similar to sounds produced by small, hard-shelled benthic invertebrates in captivity. Time-lapse photography of the reef reveals an increase in benthic invertebrate activity at sundown, consistent with an increase in sound level. The dominant acoustic phenomenon on these reefs may thus originate from the interaction between a large number of small invertebrates and the substrate. Such sounds could be used to take census of hard-shelled benthic invertebrates that are otherwise extremely difficult to survey. A two-dimensional `map' of sound production over a coral reef in the Hawaiian Islands was obtained using two-dimensional hydrophone array in the third case. Heterogeneously distributed bio-acoustic sources were generally co-located with rocky reef areas. Acoustically dominant snapping shrimp were largely restricted to one location within the area surveyed

  18. Sources of pulsed radiation

    International Nuclear Information System (INIS)

    Sauer, M.C. Jr.

    1981-01-01

    Characteristics of various sources of pulsed radiation are examined from the viewpoint of their importance to the radiation chemist, and some examples of uses of such sources are mentioned. A summary is given of the application of methods of physical dosimetry to pulsed sources, and the calibration of convenient chemical dosimeters by physical dosimetry is outlined. 7 figures, 1 table

  19. Sound source location in cavitating tip vortices

    International Nuclear Information System (INIS)

    Higuchi, H.; Taghavi, R.; Arndt, R.E.A.

    1985-01-01

    Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress

  20. Directivity of Spherical Polyhedron Sound Source Used in Near-Field HRTF Measurements

    International Nuclear Information System (INIS)

    Yu Guang-Zheng; Xie Bo-Sun; Rao Dan

    2010-01-01

    The omnidirectional character is one of important requirements for the sound source used in near-field head-related transfer function (HRTF) measurements. Based on the analysis on the radiation sound pressure and directivity character of various spherical polyhedron sound sources, a spherical dodecahedral sound source with radius of 0.035m is proposed and manufactured. Theoretical and measured results indicate that the sound source is approximately omnidirectional below the frequency of 8 kHz. In addition, the sound source has reasonable magnitude response from 350Hz to 20kHz and linear phase characteristics. Therefore, it is suitable for the near-field HRTF measurements. (fundamental areas of phenomenology(including applications))

  1. Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

    International Nuclear Information System (INIS)

    Schultz, E.

    1985-01-01

    Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

  2. Analysis of radiation fields in tomography on diffusion gaseous sound

    International Nuclear Information System (INIS)

    Bekman, I.N.

    1999-01-01

    Perspectives of application of equilibrium and stationary variants of diffusion tomography with radioactive gaseous sounds for spatial reconstruction of heterogeneous media in materials technology were considered. The basic attention were allocated to creation of simple algorithms of detection of sound accumulation on the background of monotonically varying concentration field. Algorithms of transformation of two-dimensional radiation field in three-dimensional distribution of radiation sources were suggested. The methods of analytical elongation of concentration field permitting separation of regional anomalies on the background of local ones and vice verse were discussed. It was shown that both equilibrium and stationary variants of diffusion tomography detect the heterogeneity of testing material, provide reduction of spatial distribution of elements of its structure and give an estimation of relative degree of defectiveness

  3. Directional sound beam emission from a configurable compact multi-source system

    KAUST Repository

    Zhao, Jiajun

    2018-01-12

    We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation directivity in far fields. The strong directivity formed in the presence of the enclosure is attributed to interference of sources under degenerate Mie resonances in the enclosure of anisotropic property. Our numerical simulations of sound emission from the sources demonstrate the radiation of a highly directed sound beam of unidirectional or bidirectional patterns, depending on how the sources are configured inside the enclosure. Our scheme, if achieved, can solve the challenging problem of poor directivity of a subwavelength sound system, and can guide beam forming and collimation by miniaturized devices.

  4. New sources of radiation

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly

  5. Synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    van Steenbergen, A.

    1979-01-01

    As a result of the exponential growth of the utilization of synchrotron radiation for research in the domain of the material sciences, atomic and molecular physics, biology and technology, a major construction activity has been generated towards new dedicated electron storage rings, designed optimally for synchrotron radiation applications, also, expansion programs are underway at the existing facilities, such as DORIS, SPEAR, and VEPP. In this report the basic properties of synchrotron radiation will be discussed, a short overview will be given of the existing and new facilities, some aspects of the optimization of a structure for a synchrotron radiation source will be discussed and the addition of wigglers and undulators for spectrum enhancement will be described. Finally, some parameters of an optimized synchrotron radiation source will be given.

  6. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  7. Method for measuring violin sound radiation based on bowed glissandi and its application to sound synthesis.

    Science.gov (United States)

    Perez Carrillo, Alfonso; Bonada, Jordi; Patynen, Jukka; Valimaki, Vesa

    2011-08-01

    This work presents a method for measuring and computing violin-body directional frequency responses, which are used for violin sound synthesis. The approach is based on a frame-weighted deconvolution of excitation and response signals. The excitation, consisting of bowed glissandi, is measured with piezoelectric transducers built into the bridge. Radiation responses are recorded in an anechoic chamber with multiple microphones placed at different angles around the violin. The proposed deconvolution algorithm computes impulse responses that, when convolved with any source signal (captured with the same transducer), produce a highly realistic violin sound very similar to that of a microphone recording. The use of motion sensors allows for tracking violin movements. Combining this information with the directional responses and using a dynamic convolution algorithm, helps to improve the listening experience by incorporating the violinist motion effect in stereo.

  8. Categorization of radiation sources

    International Nuclear Information System (INIS)

    Antonova, M.

    2000-01-01

    Through one-parameter (factor) analysis it is proved a hypothesis that the value of a radiation source (RS) activity of an application correlates with the category (the rank) given to it by the IAEA categorization although it is based on other parameters of the RS applications (practices like devices with radiation sources in industry, science, medicine and agriculture). The principles of the new IAEA categorization, taking into account the potential harm the sources may cause and the necessary regulatory control, are described. (author)

  9. Sound source localization and segregation with internally coupled ears

    DEFF Research Database (Denmark)

    Bee, Mark A; Christensen-Dalsgaard, Jakob

    2016-01-01

    to their correct sources (sound source segregation). Here, we review anatomical, biophysical, neurophysiological, and behavioral studies aimed at identifying how the internally coupled ears of frogs contribute to sound source localization and segregation. Our review focuses on treefrogs in the genus Hyla......, as they are the most thoroughly studied frogs in terms of sound source localization and segregation. They also represent promising model systems for future work aimed at understanding better how internally coupled ears contribute to sound source localization and segregation. We conclude our review by enumerating...

  10. Airframe related aeroacoustics of transport aircraft� -research into prediction and reduction of sound radiation-�

    OpenAIRE

    Delfs, Jan Werner

    2013-01-01

    As the sound generation in turbofan engines has decreased the significance of airframe related sound has increased. For example in landing approach the sound associated with the airframe may even dominate the overall sound radiation of an aircraft. The influence of the airframe on aerosound is threefold: i) Airframe components subjected to either their own turbulent boundary layer flow or to installation related turbulent flow act as sources of sound, ii) The aerodynamic influence of the airf...

  11. Task-Modulated Cortical Representations of Natural Sound Source Categories

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; Kassuba, Tanja; Madsen, Kristoffer Hougaard

    2018-01-01

    In everyday sound environments, we recognize sound sources and events by attending to relevant aspects of an acoustic input. Evidence about the cortical mechanisms involved in extracting relevant category information from natural sounds is, however, limited to speech. Here, we used functional MRI...

  12. Synchroton Radiation Sources

    International Nuclear Information System (INIS)

    Hulbert, S.L.; Williams, G.P.

    1998-01-01

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light

  13. Characteristics of sound radiation from turbulent premixed flames

    Science.gov (United States)

    Rajaram, Rajesh

    Turbulent combustion processes are inherently unsteady and, thus, a source of acoustic radiation, which occurs due to the unsteady expansion of reacting gases. While prior studies have extensively characterized the total sound power radiated by turbulent flames, their spectral characteristics are not well understood. The objective of this research work is to measure the flow and acoustic properties of an open turbulent premixed jet flame and explain the spectral trends of combustion noise. The flame dynamics were characterized using high speed chemiluminescence images of the flame. A model based on the solution of the wave equation with unsteady heat release as the source was developed and was used to relate the measured chemiluminescence fluctuations to its acoustic emission. Acoustic measurements were performed in an anechoic environment for several burner diameters, flow velocities, turbulence intensities, fuels, and equivalence ratios. The acoustic emissions are shown to be characterized by four parameters: peak frequency (Fpeak), low frequency slope (beta), high frequency slope (alpha) and Overall Sound Pressure Level (OASPL). The peak frequency (Fpeak) is characterized by a Strouhal number based on the mean velocity and a flame length. The transfer function between the acoustic spectrum and the spectrum of heat release fluctuations has an f2 dependence at low frequencies, while it converged to a constant value at high frequencies. Furthermore, the OASPL was found to be characterized by (Fpeak mfH)2, which resembles the source term in the wave equation.

  14. Safe handling of radiation sources

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    This chapter discussed the subjects related to the safe handling of radiation sources: type of radiation sources, method of use: transport within premises, transport outside premises; Disposal of Gamma Sources

  15. Categorization of radiation sources

    International Nuclear Information System (INIS)

    2000-12-01

    The objective of this report is to develop a categorization scheme for radiation sources that could be relevant to decisions both in a retrospective application to bring sources under control and in a prospective sense to guide the application of the regulatory infrastructure. The Action Plan envisages that the preparation of guidance on national strategies and programmes for the detection and location of orphan sources and their subsequent management should commence after the categorization of sources has been carried out. In the prospective application of the system of notification, registration, and licensing, the categorization is relevant to prioritize a regulatory authority's resources and training activities; to guide the degree of detail necessary for a safety assessment; and to serve as a measure of the intensity of effort which a regulatory authority should apply to the safety and security of a particular type of source

  16. The baffle influence on sound radiation characteristics of a plate

    Directory of Open Access Journals (Sweden)

    Bao Liu

    2017-01-01

    Full Text Available The acoustic radiation characteristics of the baffle plates and unbaffle plates are calculated and compared by single-layer potential and double-layer potential. Based on the boundary integral equation, the sound pressure integral equation of the baffle and the baffle are deduced respectively. According to the boundary compatibility condition, the sound pressure and the vibration velocity of the plates are obtained. Further, the dynamic equation of the structure is substituted into the vibration equation in the form of the baffle plate and the baffle plate. The sound pressure difference and the displacement of a plate surface are in the form of the vibration mode superposition and the acoustic radiation impedance of the double integral form is obtained, which determines vibration mode coefficient and sound radiation parameters. The effect of the baffle on the acoustic radiation characteristics of the thin plate is analyzed by comparing the acoustic radiation parameters with the simple and simple rectangular plate in water.

  17. Structure-borne sound structural vibrations and sound radiation at audio frequencies

    CERN Document Server

    Cremer, L; Petersson, Björn AT

    2005-01-01

    Structure-Borne Sound"" is a thorough introduction to structural vibrations with emphasis on audio frequencies and the associated radiation of sound. The book presents in-depth discussions of fundamental principles and basic problems, in order to enable the reader to understand and solve his own problems. It includes chapters dealing with measurement and generation of vibrations and sound, various types of structural wave motion, structural damping and its effects, impedances and vibration responses of the important types of structures, as well as with attenuation of vibrations, and sound radi

  18. The natural horn as an efficient sound radiating system ...

    African Journals Online (AJOL)

    Results obtained showed that the locally made horn are efficient sound radiating systems and are therefore excellent for sound production in local musical renditions. These findings, in addition to the portability and low cost of the horns qualify them to be highly recommended for use in music making and for other purposes ...

  19. Doses from Medical Radiation Sources

    Science.gov (United States)

    ... Medical Radiation Sources Michael G. Stabin, PhD, CHP Introduction Radiation exposures from diagnostic medical examinations are generally ... of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, mSv Skull ( ...

  20. Tuned sources of submillimetre radiation

    International Nuclear Information System (INIS)

    Berezhnyj, V.L.

    1981-01-01

    The main present directions of development of sources of frequency coherent tuned radiation of electromagnetic waves in the submillimeter range: nonlinear mixing of different frequencies; semiconductor lasers; molecular lasers with optical pumping; relativistic electron beams in a magnetic field as submillimeter radiation sources; submillimeter radiation sources on the basis of SHF classical electrovacuum devices - are considered. The designs of generator systems and their specifications are presented. The main parameters of electromagnetic radiation of different sources, such as: power, stability, frequency, tuning range - are presented. The methods of improving sources and electromagnetic radiation parameters are proposed. The examples of possible applications of submillimeter radiation in different spheres of science and technology are given [ru

  1. Future Synchrotron Radiation Sources

    CERN Document Server

    Winick, Herman

    2003-01-01

    Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose; the others, with energy up to 5 giga-electron volts (GeV), were used parasitically during the operation of the ring for high energy physics research. In addition, at that time synchrotron radiation from nine cyclic electron synchrotrons, with energy up to 5 GeV, was also used parasitically. At present no cyclic synchrotrons are used, while about 50 electron storage rings are in operation around the world as fully dedicated light sources for basic and applied research in a wide variety of fields. Among these fields are structural molecular biology, molecular environmental science, materials, analytic chemistry, micr...

  2. Radiation sources and process

    International Nuclear Information System (INIS)

    Honious, H.B.; Janzow, E.F.; Malson, H.A.; Moyer, S.E.

    1980-01-01

    The invention relates to radiation sources comprising a substrate having an electrically-conductive non-radioactive metal surface, a layer of a metal radioactive isotope of the scandium group, which in addition to scandium, yttrium, lanthanum and actinium, includes all the lanthanide and actinide series of elements, with the actinide series usually being preferred because of the nature of the radioactive isotopes therein, particularly americium-241, curium-244, plutonium-238, californium-252 and promethium-147, and a non-radioactive bonding metal codeposited on the surface by electroplating the isotope and bonding metal from an electrolytic solution, the isotope being present in the layer in minor amount as compared to the bonding metal, and with or without a non-radioactive protective metal coating covering the isotoype and bonding metal on the surface, the coating being sufficiently thin to permit radiation to pass through the coating. The invention also relates to a process for providing radiation sources comprising codepositing a layer of the metal radioactive isotope with a non-radioactive bonding metal from an electrolytic solution in which the isotope is present in minor molar amount as compared to the bonding metal such that the codeposited layer contains a minor molar amount of the isotope compared to the bonding metal by electroplating on an electrically-conductive non-radioactive metal surface of a cathode substrate, and with or without depositing a nonradioactive protective metal coating over the isotope and bonding metal on the surface, the coating being sufficiently thin to permit radiation to pass through the coating

  3. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  4. Sound Radiation of Aerodynamically Excited Flat Plates into Cavities

    Directory of Open Access Journals (Sweden)

    Johannes Osterziel

    2017-10-01

    Full Text Available Flow-induced vibrations and the sound radiation of flexible plate structures of different thickness mounted in a rigid plate are experimentally investigated. Therefore, flow properties and turbulent boundary layer parameters are determined through measurements with a hot-wire anemometer in an aeroacoustic wind tunnel. Furthermore, the excitation of the vibrating plate is examined by laser scanning vibrometry. To describe the sound radiation and the sound transmission of the flexible aluminium plates into cavities, a cuboid-shaped room with adjustable volume and 34 flush-mounted microphones is installed at the non flow-excited side of the aluminium plates. Results showed that the sound field inside the cavity is on the one hand dependent on the flow parameters and the plate thickness and on the other hand on the cavity volume which indirectly influences the level and the distribution of the sound pressure behind the flexible plate through different excited modes.

  5. Orientation Estimation and Signal Reconstruction of a Directional Sound Source

    DEFF Research Database (Denmark)

    Guarato, Francesco

    , one for each call emission, were compared to those calculated through a pre-existing technique based on interpolation of sound-pressure levels at microphone locations. The application of the method to the bat calls could provide knowledge on bat behaviour that may be useful for a bat-inspired sensor......Previous works in the literature about one tone or broadband sound sources mainly deal with algorithms and methods developed in order to localize the source and, occasionally, estimate the source bearing angle (with respect to a global reference frame). The problem setting assumes, in these cases......, omnidirectional receivers collecting the acoustic signal from the source: analysis of arrival times in the recordings together with microphone positions and source directivity cues allows to get information about source position and bearing. Moreover, sound sources have been included into sensor systems together...

  6. Natural sources of ionizing radiations

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

  7. Second Sound for Heat Source Localization

    CERN Document Server

    Vennekate, Hannes; Uhrmacher, Michael; Quadt, Arnulf; Grosse-Knetter, Joern

    2011-01-01

    Defects on the surface of superconducting cavities can limit their accelerating gradient by localized heating. This results in a phase transition to the normal conduction state | a quench. A new application, involving Oscillating Superleak Transducers (OST) to locate such quench inducing heat spots on the surface of the cavities, has been developed by D. Hartill et al. at Cornell University in 2008. The OSTs enable the detection of heat transfer via second sound in super uid helium. This thesis presents new results on the analysis of their signal. Its behavior has been studied for dierent circumstances at setups at the University of Gottingen and at CERN. New approaches for an automated signal processing have been developed. Furthermore, a rst test setup for a single-cell Superconducting Proton Linac (SPL) cavity has been prepared. Recommendations of a better signal retrieving for its operation are presented.

  8. Experience with synchrotron radiation sources

    International Nuclear Information System (INIS)

    Krinsky, S.

    1987-01-01

    The development of synchrotron radiation sources is discussed, emphasizing characteristics important for x-ray microscopy. Bending magnets, wigglers and undulators are considered as sources of radiation. Operating experience at the national Synchrotron Light Source on the VUV and XRAY storage rings is reviewed, with particular consideration given to achieved current and lifetime, transverse bunch dimensions, and orbit stability. 6 refs., 3 figs

  9. Separation of non-stationary multi-source sound field based on the interpolated time-domain equivalent source method

    Science.gov (United States)

    Bi, Chuan-Xing; Geng, Lin; Zhang, Xiao-Zheng

    2016-05-01

    In the sound field with multiple non-stationary sources, the measured pressure is the sum of the pressures generated by all sources, and thus cannot be used directly for studying the vibration and sound radiation characteristics of every source alone. This paper proposes a separation model based on the interpolated time-domain equivalent source method (ITDESM) to separate the pressure field belonging to every source from the non-stationary multi-source sound field. In the proposed method, ITDESM is first extended to establish the relationship between the mixed time-dependent pressure and all the equivalent sources distributed on every source with known location and geometry information, and all the equivalent source strengths at each time step are solved by an iterative solving process; then, the corresponding equivalent source strengths of one interested source are used to calculate the pressure field generated by that source alone. Numerical simulation of two baffled circular pistons demonstrates that the proposed method can be effective in separating the non-stationary pressure generated by every source alone in both time and space domains. An experiment with two speakers in a semi-anechoic chamber further evidences the effectiveness of the proposed method.

  10. A particle velocity based method for separating all multi incoherent sound sources

    NARCIS (Netherlands)

    Winkel, J.C.; Yntema, Doekle Reinder; Druyvesteyn, W.F.; de Bree, H.E.

    2006-01-01

    In this paper we present a method to separate the contributions of different uncorrelated sound sources to the total sound field. When the contribution of each sound source to the total sound field is known, techniques with array-applications like direct sound field measurements or inverse acoustics

  11. Sound radiation quantities arising from a resilient circular radiator

    NARCIS (Netherlands)

    Aarts, R.M.; Janssen, A.J.E.M.

    2009-01-01

    Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are

  12. Incidents with hazardous radiation sources

    International Nuclear Information System (INIS)

    Schoenhacker, Stefan

    2016-01-01

    Incidents with hazardous radiation sources can occur in any country, even those without nuclear facilities. Preparedness for such incidents is supposed to fulfill globally agreed minimum standards. Incidents are categorized in incidents with licensed handling of radiation sources as for material testing, transport accidents of hazardous radiation sources, incidents with radionuclide batteries, incidents with satellites containing radioactive inventory, incidents wit not licensed handling of illegally acquired hazardous radiation sources. The emergency planning in Austria includes a differentiation according to the consequences: incidents with release of radioactive materials resulting in restricted contamination, incidents with release of radioactive materials resulting in local contamination, and incidents with the hazard of e@nhanced exposure due to the radiation source.

  13. Offshore dredger sound: source levels, sound maps and risk assessment (abstract)

    NARCIS (Netherlands)

    Jong, C.A.F. de; Ainslie, M.A.; Heinis, F.; Janmaat, J.

    2013-01-01

    The Port of Rotterdam is expanding to meet the growing demand to accommodate large cargo vessels. One of the licensing conditions was the monitoring of the underwater sound produced during its construction, with an emphasis on the establishment of acoustic source levels of the Trailing Suction

  14. Forced sound transmission through a finite-sized single leaf panel subject to a point source excitation.

    Science.gov (United States)

    Wang, Chong

    2018-03-01

    In the case of a point source in front of a panel, the wavefront of the incident wave is spherical. This paper discusses spherical sound waves transmitting through a finite sized panel. The forced sound transmission performance that predominates in the frequency range below the coincidence frequency is the focus. Given the point source located along the centerline of the panel, forced sound transmission coefficient is derived through introducing the sound radiation impedance for spherical incident waves. It is found that in addition to the panel mass, forced sound transmission loss also depends on the distance from the source to the panel as determined by the radiation impedance. Unlike the case of plane incident waves, sound transmission performance of a finite sized panel does not necessarily converge to that of an infinite panel, especially when the source is away from the panel. For practical applications, the normal incidence sound transmission loss expression of plane incident waves can be used if the distance between the source and panel d and the panel surface area S satisfy d/S>0.5. When d/S ≈0.1, the diffuse field sound transmission loss expression may be a good approximation. An empirical expression for d/S=0  is also given.

  15. Detection of aeroacoustic sound sources on aircraft and wind turbines

    NARCIS (Netherlands)

    Oerlemans, Stefan

    2009-01-01

    This thesis deals with the detection of aeroacoustic sound sources on aircraft and wind turbines using phased microphone arrays. First, the reliability of the array technique is assessed using airframe noise measurements in open and closed wind tunnels. It is demonstrated that quantitative acoustic

  16. The effect of sound sources on soundscape appraisal

    NARCIS (Netherlands)

    van den Bosch, Kirsten; Andringa, Tjeerd

    2014-01-01

    In this paper we explore how the perception of sound sources (like traffic, birds, and the presence of distant people) influences the appraisal of soundscapes (as calm, lively, chaotic, or boring). We have used 60 one-minute recordings, selected from 21 days (502 hours) in March and July 2010.

  17. The low-frequency sound power measuring technique for an underwater source in a non-anechoic tank

    Science.gov (United States)

    Zhang, Yi-Ming; Tang, Rui; Li, Qi; Shang, Da-Jing

    2018-03-01

    In order to determine the radiated sound power of an underwater source below the Schroeder cut-off frequency in a non-anechoic tank, a low-frequency extension measuring technique is proposed. This technique is based on a unique relationship between the transmission characteristics of the enclosed field and those of the free field, which can be obtained as a correction term based on previous measurements of a known simple source. The radiated sound power of an unknown underwater source in the free field can thereby be obtained accurately from measurements in a non-anechoic tank. To verify the validity of the proposed technique, a mathematical model of the enclosed field is established using normal-mode theory, and the relationship between the transmission characteristics of the enclosed and free fields is obtained. The radiated sound power of an underwater transducer source is tested in a glass tank using the proposed low-frequency extension measuring technique. Compared with the free field, the radiated sound power level of the narrowband spectrum deviation is found to be less than 3 dB, and the 1/3 octave spectrum deviation is found to be less than 1 dB. The proposed testing technique can be used not only to extend the low-frequency applications of non-anechoic tanks, but also for measurement of radiated sound power from complicated sources in non-anechoic tanks.

  18. The sources of radiation exposure

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1992-01-01

    Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)

  19. Ionizing radiations: effects and sources

    International Nuclear Information System (INIS)

    Vignes, S.; Nenot, J.C.

    1978-01-01

    Having first mentioned the effects of ionizing radiations in cancerogenisis, pre-natal, and genetic fields, the authors present the different sources of radiations and estimate their respective contributions to the total irradiation dose. Their paper makes reference to the main elements of a report issued by the United Nations Scientific Committee in 1977 [fr

  20. Acoustic resonators for the reduction of sound radiation and transmission

    NARCIS (Netherlands)

    Hannink, M.H.C.

    2007-01-01

    Noise is a frequently encountered problem in modern society. One of the environments where the presence of noise causes a deterioration in people’s comfort is in aircraft cabins. For modern aircraft flying at cruise conditions, the main sound source is the turbulent boundary layer around the

  1. Searching for Orphan radiation sources

    International Nuclear Information System (INIS)

    Bystrov, Evgenij; Antonau, Uladzimir; Gurinovich, Uladzimir; Kazhamiakin, Valery; Petrov, Vitaly; Shulhovich, Heorhi; Tischenko, Siarhei

    2008-01-01

    Full text: The problem of orphan sources cannot be left unaddressed due high probability of accidental exposure and use of sources for terrorism. Search of objects of this kind is complex particularly when search territory is large. This requires devices capable of detecting sources, identifying their radionuclide composition, and correlating scan results to geographical coordinates and displaying results on a map. Spectral radiation scanner AT6101C can fulfill the objective of search for gamma and neutron radiation sources, radionuclide composition identification, correlation results to geographical coordinates and displaying results on a map. The scanner consists of gamma radiation scintillation detection unit based on NaI(Tl) crystal, neutron detection unit based on two He 3 counters, GPS receiver and portable ruggedized computer. Built-in and application software automates entire scan process, saving all results to memory for further analysis with visual representation of results as spectral information diagrams, count rate profile and gamma radiation dose rates on a geographical map. The scanner informs operator with voice messages on detection of radiation sources, identification result and other events. Scanner detection units and accessories are packed in a backpack. Weighing 7 kg, the scanner is human portable and can be used for scan inside cars. The scanner can also be used for radiation mapping and inspections. (author)

  2. Sound radiation quantities arising from a resilient circular radiator.

    Science.gov (United States)

    Aarts, Ronald M; Janssen, Augustus J E M

    2009-10-01

    Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are either Stenzel functions (1-(sigma/a)2)n, with sigma the radial coordinate on the radiator, or linear combinations of Zernike functions Pn(2(sigma/a)2-1), with Pn the Legendre polynomial of degree n. Both sets of functions give rise, via King's integral for the pressure, to integrals for the quantities of interest involving the product of two Bessel functions. These integrals have a power series expansion and allow an expression in terms of Bessel functions of the first kind and Struve functions. Consequently, many of the results in [M. Greenspan, J. Acoust. Soc. Am. 65, 608-621 (1979)] are generalized and treated in a unified manner. A foreseen application is for loudspeakers. The relation between the radiated power in the near-field on one hand and in the far field on the other is highlighted.

  3. Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

    Science.gov (United States)

    Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

    2016-01-01

    A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates over the evanescent sound field because of broadening of the wavenumber spectrum. Therefore, we calculated the optimum distribution of the particle velocity on the vibrating plate to reduce the broadening of the wavenumber spectrum. We focused on a window function that is utilized in the field of signal analysis for reducing the broadening of the frequency spectrum. The optimization calculation is necessary for the design of window function suitable for suppressing sound radiation and securing a spatial area for data communication. In addition, a wide frequency bandwidth is required to increase the data transmission speed. Therefore, we investigated a suitable method for calculating the sound pressure level at the far field to confirm the variation of the distribution of sound pressure level determined on the basis of the window shape and frequency. The distribution of the sound pressure level at a finite distance was in good agreement with that obtained at an infinite far field under the condition generating the evanescent sound field. Consequently, the window function was optimized by the method used to calculate the distribution of the sound pressure level at an infinite far field using the wavenumber spectrum on the vibrating plate. According to the result of comparing the distributions of the sound pressure level in the cases with and without the window function, it was confirmed that the area whose sound pressure level was reduced from the maximum level to -50 dB was

  4. Reconstruction of Sound Source Pressures in an Enclosure Using the Phased Beam Tracing Method

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon

    2009-01-01

    . First, surfaces of an extended source are divided into reasonably small segments. From each source segment, one beam is projected into the field and all emitted beams are traced. Radiated beams from the source reach array sensors after traveling various paths including the wall reflections. Collecting...... all the pressure histories at the field points, source-observer relations can be constructed in a matrix-vector form for each frequency. By multiplying the measured field data with the pseudo-inverse of the calculated transfer function, one obtains the distribution of source pressure. An omni......-directional sphere and a cubic source in a rectangular enclosure were taken as examples in the simulation tests. A reconstruction error was investigated by Monte Carlo simulation in terms of field point locations. When the source information was reconstructed by the present method, it was shown that the sound power...

  5. Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

    Science.gov (United States)

    Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

    2017-08-01

    Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

  6. Radiation sources working group summary

    International Nuclear Information System (INIS)

    Fazio, M.V.

    1998-01-01

    The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, components technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigation, and phenomena that impact source design such as fatigue in resonant structures due to RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations

  7. Detection of aeroacoustic sound sources on aircraft and wind turbines

    International Nuclear Information System (INIS)

    Oerlemans, S.

    2009-01-01

    This thesis deals with the detection of aeroacoustic sound sources on aircraft and wind turbines using phased microphone arrays. First, the reliability of the array technique is assessed using airframe noise measurements in open and closed wind tunnels. It is demonstrated that quantitative acoustic measurements are possible in both wind tunnels. Then, the array technique is applied to characterize the noise sources on two modern large wind turbines. It is shown that practically all noise emitted to the ground is produced by the outer part of the blades during their downward movement. This asymmetric source pattern, which causes the typical swishing noise during the passage of the blades, can be explained by trailing edge noise directivity and convective amplification. Next, a semi-empirical prediction method is developed for the noise from large wind turbines. The prediction code is successfully validated against the experimental results, not only with regard to sound levels, spectra, and directivity, but also with regard to the noise source distribution in the rotor plane and the temporal variation in sound level (swish). The validated prediction method is then applied to calculate wind turbine noise footprints, which show that large swish amplitudes can occur even at large distance. The influence of airfoil shape on blade noise is investigated through acoustic wind tunnel tests on a series of wind turbine airfoils. Measurements are carried out at various wind speeds and angles of attack, with and without upstream turbulence and boundary layer tripping. The speed dependence, directivity, and tonal behaviour are determined for both trailing edge noise and inflow turbulence noise. Finally, two noise reduction concepts are tested on a large wind turbine: acoustically optimized airfoils and trailing edge serrations. Both blade modifications yield a significant trailing edge noise reduction at low frequencies, but also cause increased tip noise at high frequencies

  8. Noise source separation of diesel engine by combining binaural sound localization method and blind source separation method

    Science.gov (United States)

    Yao, Jiachi; Xiang, Yang; Qian, Sichong; Li, Shengyang; Wu, Shaowei

    2017-11-01

    In order to separate and identify the combustion noise and the piston slap noise of a diesel engine, a noise source separation and identification method that combines a binaural sound localization method and blind source separation method is proposed. During a diesel engine noise and vibration test, because a diesel engine has many complex noise sources, a lead covering method was carried out on a diesel engine to isolate other interference noise from the No. 1-5 cylinders. Only the No. 6 cylinder parts were left bare. Two microphones that simulated the human ears were utilized to measure the radiated noise signals 1 m away from the diesel engine. First, a binaural sound localization method was adopted to separate the noise sources that are in different places. Then, for noise sources that are in the same place, a blind source separation method is utilized to further separate and identify the noise sources. Finally, a coherence function method, continuous wavelet time-frequency analysis method, and prior knowledge of the diesel engine are combined to further identify the separation results. The results show that the proposed method can effectively separate and identify the combustion noise and the piston slap noise of a diesel engine. The frequency of the combustion noise and the piston slap noise are respectively concentrated at 4350 Hz and 1988 Hz. Compared with the blind source separation method, the proposed method has superior separation and identification effects, and the separation results have fewer interference components from other noise.

  9. High frequency ion sound waves associated with Langmuir waves in type III radio burst source regions

    Directory of Open Access Journals (Sweden)

    G. Thejappa

    2004-01-01

    Full Text Available Short wavelength ion sound waves (2-4kHz are detected in association with the Langmuir waves (~15-30kHz in the source regions of several local type III radio bursts. They are most probably not due to any resonant wave-wave interactions such as the electrostatic decay instability because their wavelengths are much shorter than those of Langmuir waves. The Langmuir waves occur as coherent field structures with peak intensities exceeding the Langmuir collapse thresholds. Their scale sizes are of the order of the wavelength of an ion sound wave. These Langmuir wave field characteristics indicate that the observed short wavelength ion sound waves are most probably generated during the thermalization of the burnt-out cavitons left behind by the Langmuir collapse. Moreover, the peak intensities of the observed short wavelength ion sound waves are comparable to the expected intensities of those ion sound waves radiated by the burnt-out cavitons. However, the speeds of the electron beams derived from the frequency drift of type III radio bursts are too slow to satisfy the needed adiabatic ion approximation. Therefore, some non-linear process such as the induced scattering on thermal ions most probably pumps the beam excited Langmuir waves towards the lower wavenumbers, where the adiabatic ion approximation is justified.

  10. Sound quality prediction for engine-radiated noise

    Science.gov (United States)

    Liu, Hai; Zhang, Junhong; Guo, Peng; Bi, Fengrong; Yu, Hanzhengnan; Ni, Guangjian

    2015-05-01

    Diesel engine-radiated noise quality prediction is an important topic because engine noise has a significant impact on the overall vehicle noise. Sound quality prediction is based on subjective and objective evaluation of engine noise. The integrated satisfaction index (ISI) is proposed as a criterion for differentiate noise quality in the subjective evaluation, and five psychoacoustic parameters are selected for characterizing and analyzing the noise quality of the diesel engine objectively. The combination of support vector machines (SVM) and genetic algorithm (GA) is proposed in order to establish a model for predicting the diesel engine-radiated noise quality for all operation conditions. The performance of the GA-SVM model is compared with the BP neural network model, and the results show that the mean relative error of the GA-SVM model is smaller than the BP neural network model. The importance rank of the sound quality metrics to the ISI is indicated by the non-parametric correlation analysis. This study suggests that the GA-SVM model is very useful for accurately predicting the diesel engine-radiated noise quality.

  11. Extended nonnegative tensor factorisation models for musical sound source separation.

    Science.gov (United States)

    FitzGerald, Derry; Cranitch, Matt; Coyle, Eugene

    2008-01-01

    Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.

  12. Extended Nonnegative Tensor Factorisation Models for Musical Sound Source Separation

    Directory of Open Access Journals (Sweden)

    Derry FitzGerald

    2008-01-01

    Full Text Available Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.

  13. Spatial resolution limits for the localization of noise sources using direct sound mapping

    DEFF Research Database (Denmark)

    Comesana, D. Fernandez; Holland, K. R.; Fernandez Grande, Efren

    2016-01-01

    the relationship between spatial resolution, noise level and geometry. The proposed expressions are validated via simulations and experiments. It is shown that particle velocity mapping yields better results for identifying closely spaced sound sources than sound pressure or sound intensity, especially...... extensively been used for many years to locate sound sources. However, it is not yet well defined when two sources should be regarded as resolved by means of direct sound mapping. This paper derives the limits of the direct representation of sound pressure, particle velocity and sound intensity by exploring......One of the main challenges arising from noise and vibration problems is how to identify the areas of a device, machine or structure that produce significant acoustic excitation, i.e. the localization of main noise sources. The direct visualization of sound, in particular sound intensity, has...

  14. Effects of Freestream Turbulence on Cavity Tone and Sound Source

    Directory of Open Access Journals (Sweden)

    Hiroshi Yokoyama

    2016-01-01

    Full Text Available To clarify the effects of freestream turbulence on cavity tones, flow and acoustic fields were directly predicted for cavity flows with various intensities of freestream turbulence. The freestream Mach number was 0.09 and the Reynolds number based on the cavity length was 4.0 × 104. The depth-to-length ratio of the cavity, D/L, was 0.5 and 2.5, where the acoustic resonance of a depth-mode occurs for D/L = 2.5. The incoming boundary layer was laminar. The results for the intensity of freestream turbulence of Tu = 2.3% revealed that the reduced level of cavity tones in a cavity flow with acoustic resonance (D/L=2.5 was greater than that without acoustic resonance (D/L=0.5. To clarify the reason for this, the sound source based on Lighthill’s acoustic analogy was computed, and the contributions of the intensity and spanwise coherence of the sound source to the reduction of the cavity tone were estimated. As a result, the effects of the reduction of spanwise coherence on the cavity tone were greater in the cavity flow with acoustic resonance than in that without resonance, while the effects of the intensity were comparable for both flows.

  15. Overview of terahertz radiation sources

    International Nuclear Information System (INIS)

    Gallerano, G.P.; Biedron, S.G.

    2004-01-01

    Although terahertz (THz) radiation was first observed about hundred years ago, the corresponding portion of the electromagnetic spectrum has been for long time considered a rather poorly explored region at the boundary between the microwaves and the infrared. This situation has changed during the past ten years with the rapid development of coherent THz sources, such as solid state oscillators, quantum cascade lasers, optically pumped solid state devices and novel free electron devices, which have in turn stimulated a wide variety of applications from material science to telecommunications, from biology to biomedicine. For a comprehensive review of THz technology the reader is addressed to a recent paper by P. Siegel. In this paper we focus on the development and perspectives of THz radiation sources.

  16. Fabrication of sealed radiation sources

    International Nuclear Information System (INIS)

    Mars, Jean.

    1977-01-01

    The description is given for fabricating a sealed radiation source, consisting in depositing on a metal substrate a thin active coat of a radioelement, termed first coat, submitting this coated substrate to an oxidation treatment in order to obtain on the first coat an inactive coat of an oxide of the metal, termed second coat, and depositing a coat of varnish on this second inactive coat [fr

  17. Movement and Perceptual Strategies to Intercept Virtual Sound Sources.

    Directory of Open Access Journals (Sweden)

    Naeem eKomeilipoor

    2015-05-01

    Full Text Available To intercept a moving object, one needs to be in the right place at the right time. In order to do this, it is necessary to pick up and use perceptual information that specifies the time to arrival of an object at an interception point. In the present study, we examined the ability to intercept a laterally moving virtual sound object by controlling the displacement of a sliding handle and tested whether and how the interaural time difference (ITD could be the main source of perceptual information for successfully intercepting the virtual object. The results revealed that in order to accomplish the task, one might need to vary the duration of the movement, control the hand velocity and time to reach the peak velocity (speed coupling, while the adjustment of movement initiation did not facilitate performance. Furthermore, the overall performance was more successful when subjects employed a time-to-contact (tau coupling strategy. This result shows that prospective information is available in sound for guiding goal-directed actions.

  18. Sound Photographs to reveal vehicle pass-by sources with a calibrated source-strength level

    NARCIS (Netherlands)

    Mast, A.; Dool, T.C. van den; Toorn, J.D. van der; Watts, G.

    2003-01-01

    In national and European discussions, it appears that the conventional sound measurement techniques are insufficient to answer some relevant questions with respect to source strength of road vehicles. An example of such a question is: What is the importance of tyre-road noise on the one hand and

  19. Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment

    Directory of Open Access Journals (Sweden)

    Ignacio Spiousas

    2017-06-01

    Full Text Available Previous studies on the effect of spectral content on auditory distance perception (ADP focused on the physically measurable cues occurring either in the near field (low-pass filtering due to head diffraction or when the sound travels distances >15 m (high-frequency energy losses due to air absorption. Here, we study how the spectrum of a sound arriving from a source located in a reverberant room at intermediate distances (1–6 m influences the perception of the distance to the source. First, we conducted an ADP experiment using pure tones (the simplest possible spectrum of frequencies 0.5, 1, 2, and 4 kHz. Then, we performed a second ADP experiment with stimuli consisting of continuous broadband and bandpass-filtered (with center frequencies of 0.5, 1.5, and 4 kHz and bandwidths of 1/12, 1/3, and 1.5 octave pink-noise clips. Our results showed an effect of the stimulus frequency on the perceived distance both for pure tones and filtered noise bands: ADP was less accurate for stimuli containing energy only in the low-frequency range. Analysis of the frequency response of the room showed that the low accuracy observed for low-frequency stimuli can be explained by the presence of sparse modal resonances in the low-frequency region of the spectrum, which induced a non-monotonic relationship between binaural intensity and source distance. The results obtained in the second experiment suggest that ADP can also be affected by stimulus bandwidth but in a less straightforward way (i.e., depending on the center frequency, increasing stimulus bandwidth could have different effects. Finally, the analysis of the acoustical cues suggests that listeners judged source distance using mainly changes in the overall intensity of the auditory stimulus with distance rather than the direct-to-reverberant energy ratio, even for low-frequency noise bands (which typically induce high amount of reverberation. The results obtained in this study show that, depending on

  20. Radiation studies in the antiproton source

    International Nuclear Information System (INIS)

    Church, M.

    1990-01-01

    Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage

  1. Competing sound sources reveal spatial effects in cortical processing.

    Directory of Open Access Journals (Sweden)

    Ross K Maddox

    Full Text Available Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention.

  2. Sound radiation contrast in MR phase images. Method for the representation of elasticity, sound damping, and sound impedance changes

    International Nuclear Information System (INIS)

    Radicke, Marcus

    2009-01-01

    The method presented in this thesis combines ultrasound techniques with the magnetic-resonance tomography (MRT). An ultrasonic wave generates in absorbing media a static force in sound-propagation direction. The force leads at sound intensities of some W/cm 2 and a sound frequency in the lower MHz range to a tissue shift in the micrometer range. This tissue shift depends on the sound power, the sound frequency, the sound absorption, and the elastic properties of the tissue. A MRT sequence of the Siemens Healthcare AG was modified so that it measures (indirectly) the tissue shift, codes as grey values, and presents as 2D picture. By means of the grey values the sound-beam slope in the tissue can be visualized, and so additionally sound obstacles (changes of the sound impedance) can be detected. By the MRT images token up spatial changes of the tissue parameters sound absorption and elasticity can be detected. In this thesis measurements are presented, which show the feasibility and future chances of this method especially for the mammary-cancer diagnostics. [de

  3. Measurement of energetic radiation caused by thunderstorm activities by a sounding balloon and ground observation

    Science.gov (United States)

    Torii, T.

    2015-12-01

    Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, and the ground observation. On the measurement inside/above the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for gamma-rays, and for beta/gamma-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of two GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the gamma-rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Furthermore, we carried out a ground observation of the energetic gamma rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the AGU meeting.

  4. Optimal Prediction of Moving Sound Source Direction in the Owl.

    Directory of Open Access Journals (Sweden)

    Weston Cox

    2015-07-01

    Full Text Available Capturing nature's statistical structure in behavioral responses is at the core of the ability to function adaptively in the environment. Bayesian statistical inference describes how sensory and prior information can be combined optimally to guide behavior. An outstanding open question of how neural coding supports Bayesian inference includes how sensory cues are optimally integrated over time. Here we address what neural response properties allow a neural system to perform Bayesian prediction, i.e., predicting where a source will be in the near future given sensory information and prior assumptions. The work here shows that the population vector decoder will perform Bayesian prediction when the receptive fields of the neurons encode the target dynamics with shifting receptive fields. We test the model using the system that underlies sound localization in barn owls. Neurons in the owl's midbrain show shifting receptive fields for moving sources that are consistent with the predictions of the model. We predict that neural populations can be specialized to represent the statistics of dynamic stimuli to allow for a vector read-out of Bayes-optimal predictions.

  5. Sound

    CERN Document Server

    Robertson, William C

    2003-01-01

    Muddled about what makes music? Stuck on the study of harmonics? Dumbfounded by how sound gets around? Now you no longer have to struggle to teach concepts you really don t grasp yourself. Sound takes an intentionally light touch to help out all those adults science teachers, parents wanting to help with homework, home-schoolers seeking necessary scientific background to teach middle school physics with confidence. The book introduces sound waves and uses that model to explain sound-related occurrences. Starting with the basics of what causes sound and how it travels, you'll learn how musical instruments work, how sound waves add and subtract, how the human ear works, and even why you can sound like a Munchkin when you inhale helium. Sound is the fourth book in the award-winning Stop Faking It! Series, published by NSTA Press. Like the other popular volumes, it is written by irreverent educator Bill Robertson, who offers this Sound recommendation: One of the coolest activities is whacking a spinning metal rod...

  6. Sound source measurement by using a passive sound insulation and a statistical approach

    Science.gov (United States)

    Dragonetti, Raffaele; Di Filippo, Sabato; Mercogliano, Francesco; Romano, Rosario A.

    2015-10-01

    This paper describes a measurement technique developed by the authors that allows carrying out acoustic measurements inside noisy environments reducing background noise effects. The proposed method is based on the integration of a traditional passive noise insulation system with a statistical approach. The latter is applied to signals picked up by usual sensors (microphones and accelerometers) equipping the passive sound insulation system. The statistical approach allows improving of the sound insulation given only by the passive sound insulation system at low frequency. The developed measurement technique has been validated by means of numerical simulations and measurements carried out inside a real noisy environment. For the case-studies here reported, an average improvement of about 10 dB has been obtained in a frequency range up to about 250 Hz. Considerations on the lower sound pressure level that can be measured by applying the proposed method and the measurement error related to its application are reported as well.

  7. Regulatory control of radiation sources in Slovakia

    International Nuclear Information System (INIS)

    Auxtova, L.

    2001-01-01

    In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

  8. High energy particle accelerators as radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

  9. Radiation attenuation gauge with magnetically coupled source

    International Nuclear Information System (INIS)

    Wallace, S.A.

    1978-01-01

    Disclosed is a radiation attenuation gauge for measuring thickness and density of a material which includes, in combination, a source of gamma radiation contained within a housing of magnetic or ferromagnetic material, and a means for measuring the intensity of gamma radiation. The measuring means has an aperture and magnetic means disposed adjacent to the aperture for attracting and holding the housed source in position before the aperture. The material to be measured is placed between the source and the measuring means

  10. Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

    Science.gov (United States)

    Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

    2006-12-01

    A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

  11. Control of radiation sources in Japan

    International Nuclear Information System (INIS)

    Maki, S.

    2001-01-01

    The report refers to the regulations for radioactive material in force in Japan, and to the organizations with responsibilities for regulating radiation sources. An outline of the law regulating the use of radiation sources and radioactive materials is provided, including its scope, types of radiation sources under control, exemptions and the system of notification, authorization and inspection. The experience of Japan with orphan sources is presented in three different cases, and the measures carried out to store the orphan sources in safe conditions. (author)

  12. Regulation for radiation protection in applications of radiation sources

    International Nuclear Information System (INIS)

    Sonawane, Avinash U.

    2016-01-01

    Applications of ionising radiation in multifarious field are increasing in the country for the societal benefits. The national regulatory body ensures safety and security of radiation sources by enforcing provisions in the national law and other relevant rules issued under the principle law. In addition, the enforcement of detailed requirements contained in practice specific safety codes and standard and issuance of safety directives brings effectiveness in ensuring safe handling and secure management of radiation sources. The regulatory requirements for control over radiation sources throughout their life-cycle have evolved over the years from experience gained. Nevertheless, some of the regulatory activities which require special attention have been identified such as the development of regulation to deal with advance emerging radiation technology in applications of radiation in medicine and industry; sustaining continuity in ensuring human resource development programme; inspections of category 3 and 4 disused sources and their safe disposal; measures for controlling transboundary movement of radiation sources. The regulatory measures have been contemplated and are being enforced to deal with the above issues in an effective manner. The complete involvement of the management of radiation facilities, radiation workers and their commitment in establishing and maintaining safety and security culture is essential to handle the radiation sources safely and efficiently at all times

  13. Source Separation of Heartbeat Sounds for Effective E-Auscultation

    Science.gov (United States)

    Geethu, R. S.; Krishnakumar, M.; Pramod, K. V.; George, Sudhish N.

    2016-03-01

    This paper proposes a cost effective solution for improving the effectiveness of e-auscultation. Auscultation is the most difficult skill for a doctor, since it can be acquired only through experience. The heart sound mixtures are captured by placing the four numbers of sensors at appropriate auscultation area in the body. These sound mixtures are separated to its relevant components by a statistical method independent component analysis. The separated heartbeat sounds can be further processed or can be stored for future reference. This idea can be used for making a low cost, easy to use portable instrument which will be beneficial to people living in remote areas and are unable to take the advantage of advanced diagnosis methods.

  14. Radiation protection problems with sealed Pu radiation sources

    International Nuclear Information System (INIS)

    Naumann, M.; Wels, C.

    1982-01-01

    A brief outline of the production methods and most important properties of Pu-238 and Pu-239 is given, followed by an overview of possibilities for utilizing the different types of radiation emitted, a description of problems involved in the safe handling of Pu radiation sources, and an assessment of the design principles for Pu-containing alpha, photon, neutron and energy sources from the radiation protection point of view. (author)

  15. Radiation effects on light sources and detectors

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1985-01-01

    The rapidly expanding field of optoelectronics includes a wide variety of both military and non-military applications in which the systems must meet radiation exposure requirements. Herein, we review the work on radiation effects on sources and detectors for such optoelectronic systems. For sources the principal problem is permanent damage-induced light output degradation, while for detectors it is ionizing radiation-induced photocurrents

  16. Regulated control of practices and radiation sources

    International Nuclear Information System (INIS)

    1992-01-01

    Excepting the radiation caused by the natural background radiation, the Executive Secretariat for Nuclear Affairs (SEAN) does not authorize any source no practice within the national territory that may imply exposure of a person to ionizing radiation unless this use is ruled. This document establishes the basic criteria to set up such system as well as to exclude or exempt practices and sources from this regulated control

  17. Radiation sources, radiation environment and risk level at Dubna

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1991-01-01

    The overall information about ionizing radiation sources, which form radiation environment and risk at Dubna, is introduced. Systematization of the measurement results is performed on the basis of the effective dose and losses of life expectancy. The contribution of different sources to total harm of Dubna inhabitants has been revealed. JINR sources carry in ∼ 4% from the total effective dose of natural and medicine radiation sources; the harm from them is much less than the harm from cigarette smoking. 18 refs.; 2 tabs

  18. Analysis, Design and Implementation of an Embedded Realtime Sound Source Localization System Based on Beamforming Theory

    Directory of Open Access Journals (Sweden)

    Arko Djajadi

    2009-12-01

    Full Text Available This project is intended to analyze, design and implement a realtime sound source localization system by using a mobile robot as the media. The implementated system uses 2 microphones as the sensors, Arduino Duemilanove microcontroller system with ATMega328p as the microprocessor, two permanent magnet DC motors as the actuators for the mobile robot and a servo motor as the actuator to rotate the webcam directing to the location of the sound source, and a laptop/PC as the simulation and display media. In order to achieve the objective of finding the position of a specific sound source, beamforming theory is applied to the system. Once the location of the sound source is detected and determined, the choice is either the mobile robot will adjust its position according to the direction of the sound source or only webcam will rotate in the direction of the incoming sound simulating the use of this system in a video conference. The integrated system has been tested and the results show the system could localize in realtime a sound source placed randomly on a half circle area (0 - 1800 with a radius of 0.3m - 3m, assuming the system is the center point of the circle. Due to low ADC and processor speed, achievable best angular resolution is still limited to 25o.

  19. Radiation exposure by using unsealed radiation sources

    International Nuclear Information System (INIS)

    Preitfellner, J.

    1999-05-01

    Investigations on patients using radioactive substances are performed on a routinely basis in nuclear medicine facilities at many hospitals in our days. These investigations are performed by administering a radiopharmacon to the patient which, depending on several parameters, remains in the body of the patient for various periods of time. All these investigations have in common a g-ray exposure of the environment by the radioactive substance in the body of the patient. Among others, doctors, technical personnel, cleaning personnel, and accompanying persons of patients are exposed to g-rays. Based on these facts, the degree of danger for persons who get into contact with these patients is repeatedly questioned. An additional problem is the health risk of persons employed at a nuclear medicine facility. To answer the first question, the local dose rate in the environment of 102 patients was evaluated immediately after application of the radioactive substance, in intervals from 30 minutes up to several hours, over a period of up to 2 weeks. Depending on the nature of the investigation, the patients were subdivided into 6 groups of 16-20 persons. From the data measured, the effective and the biological half life as well as the local dose were computed. With the aid of concrete case examples, the possible radiation exposure for contact persons was estimated. Postulating unfavorable local and temporal factors in our estimations, the actual radiation exposure is to be estimated about 10-30 % lower. As a reference value for the danger of persons, the maximum permissible boundary values from the Austrian Regulations for Protection against Radiation were used. Referring to these boundary values, for none of the six nuclear medicine investigation methods a danger for contact persons could be derived, indicating that available security measures offer a sufficient protection for affected contact persons. To answer the question about the risk for persons employed at a nuclear

  20. Sensitivity to plant modelling uncertainties in optimal feedback control of sound radiation from a panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1997-01-01

    Optimal feedback control of broadband sound radiation from a rectangular baffled panel has been investigated through computer simulations. Special emphasis has been put on the sensitivity of the optimal feedback control to uncertainties in the modelling of the system under control.A model...... in terms of a set of radiation filters modelling the radiation dynamics.Linear quadratic feedback control applied to the panel in order to minimise the radiated sound power has then been simulated. The sensitivity of the model based controller to modelling uncertainties when using feedback from actual...

  1. Sources of underwater sound and their characterisation (abstract)

    NARCIS (Netherlands)

    Ainslie, M.A.; Jong, C.A.F. de

    2013-01-01

    After centuries of speculation, punctuated by occasional theoretical or experimental advances, the first intensive research into underwater sound took place 100 years ago, applied initially to provide advance warning of icebergs after the loss of RMS Titanic in 1912, and later to counter the U-boat

  2. Active structural acoustic control for reduction of radiated sound from structure

    International Nuclear Information System (INIS)

    Hong, Jin Seok; Oh, Jae Eung

    2001-01-01

    Active control of sound radiation from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Structural excitation is achieved by two piezoceramic actuators mounted on the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The approach is based on a multi-channel filtered-x LMS algorithm. The results shows that attenuation of sound levels of 11dB, 10dB is achieved

  3. A SOUND SOURCE LOCALIZATION TECHNIQUE TO SUPPORT SEARCH AND RESCUE IN LOUD NOISE ENVIRONMENTS

    Science.gov (United States)

    Yoshinaga, Hiroshi; Mizutani, Koichi; Wakatsuki, Naoto

    At some sites of earthquakes and other disasters, rescuers search for people buried under rubble by listening for the sounds which they make. Thus developing a technique to localize sound sources amidst loud noise will support such search and rescue operations. In this paper, we discuss an experiment performed to test an array signal processing technique which searches for unperceivable sound in loud noise environments. Two speakers simultaneously played a noise of a generator and a voice decreased by 20 dB (= 1/100 of power) from the generator noise at an outdoor space where cicadas were making noise. The sound signal was received by a horizontally set linear microphone array 1.05 m in length and consisting of 15 microphones. The direction and the distance of the voice were computed and the sound of the voice was extracted and played back as an audible sound by array signal processing.

  4. Reconstruction of sound source signal by analytical passive TR in the environment with airflow

    Science.gov (United States)

    Wei, Long; Li, Min; Yang, Debin; Niu, Feng; Zeng, Wu

    2017-03-01

    In the acoustic design of air vehicles, the time-domain signals of noise sources on the surface of air vehicles can serve as data support to reveal the noise source generation mechanism, analyze acoustic fatigue, and take measures for noise insulation and reduction. To rapidly reconstruct the time-domain sound source signals in an environment with flow, a method combining the analytical passive time reversal mirror (AP-TR) with a shear flow correction is proposed. In this method, the negative influence of flow on sound wave propagation is suppressed by the shear flow correction, obtaining the corrected acoustic propagation time delay and path. Those corrected time delay and path together with the microphone array signals are then submitted to the AP-TR, reconstructing more accurate sound source signals in the environment with airflow. As an analytical method, AP-TR offers a supplementary way in 3D space to reconstruct the signal of sound source in the environment with airflow instead of the numerical TR. Experiments on the reconstruction of the sound source signals of a pair of loud speakers are conducted in an anechoic wind tunnel with subsonic airflow to validate the effectiveness and priorities of the proposed method. Moreover the comparison by theorem and experiment result between the AP-TR and the time-domain beamforming in reconstructing the sound source signal is also discussed.

  5. Active control of radiated sound power from a baffled, rectangular panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1996-01-01

    with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over......Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... a broad frequency range using few piezoceramic actuators, provided that an accurate estimate of the sound power is available for minimisation....

  6. Reproduction of nearby sound sources using higher-order ambisonics with practical loudspeaker arrays

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2012-01-01

    the impact of two existing and a new proposed regularization function on the reproduced sound fields and on the main auditory cue for nearby sound sources outside the median plane, i.e, low-frequencies interaural level differences (ILDs). The proposed regularization function led to a better reproduction......In order to reproduce nearby sound sources with distant loudspeakers to a single listener, the near field compensated (NFC) method for higher-order Ambisonics (HOA) has been previously proposed. In practical realization, this method requires the use of regularization functions. This study analyzes...... of point source sound fields compared to existing regularization functions for NFC-HOA. Measurements in realistic playback environments showed that, for very close sources, significant ILDs for frequencies above about 250 Hz can be reproduced with NFC-HOA and the proposed regularization function whereas...

  7. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde, Raymond Keegan

    2008-07-01

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  8. Radiation safety and inventory of sealed radiation sources in Pakistan

    International Nuclear Information System (INIS)

    Ali, M.; Mannan, A.

    2001-01-01

    Sealed radiation sources (SRS) of various types and activities are widely used in industry, medicine, agriculture, research and teaching in Pakistan. The proper maintenance of records of SRS is mandatory for users/licensees. Since 1956, more than 2000 radiation sources of different isotopes having activities of Bq to TBq have been imported. Of these, several hundred sources have been disposed of and some have been exported/returned to the suppliers. To ensure the safety and security of the sources and to control and regulate the safe use of radiation sources in various disciplines, the Directorate of Nuclear Safety and Radiation Protection (DNSRP), the implementing arm of the regulatory authority in the country, has introduced a system for notifying, registering and licensing the use of all types of SRS. In order to update the inventory of SRS used throughout the country, the DNSRP has developed a database. (author)

  9. Radiation sources and methods for producing them

    International Nuclear Information System (INIS)

    Malson, H.A.; Moyer, S.E.; Honious, H.B.; Janzow, E.F.

    1979-01-01

    The radiation sources contain a substrate with an electrically conducting, non-radioactive metal surface, a layer of a metal isotope of the scandium group as well as a percentage of non-radioactive binding metal being coated on the surface by means of an electroplating method. Besides examples for β sources ( 147 Pm), γ sources ( 241 Am), and neutron sources ( 252 Cf) there is described an α-radiation source ( 241 Am, 244 Cu, 238 Pu) for smoke detectors. There are given extensive tables and a bibliography. (DG) [de

  10. Sources of radiation exposure - an overview

    International Nuclear Information System (INIS)

    Mason, G.C.

    1990-01-01

    Sources of radiation exposure are reviewed from the perspective of mining and milling of radioactive ores in Australia. The major sources of occupational and public exposure are identified and described, and exposures from mining and milling operations are discussed in the context of natural radiation sources and other sources arising from human activities. Most radiation exposure of humans comes from natural sources. About 80% of the world average of the effective dose equivalents received by individual people arises from natural radiation, with a further 15-20% coming from medical exposures*. Exposures results from human activities, such as mining and milling of radioactive ores, nuclear power generation, fallout from nuclear weapons testing and non-medical use of radioisotopes and X-rays, add less than 1% to the total. 9 refs., 4 tabs., 10 figs

  11. Differences in directional sound source behavior and perception between assorted computer room models

    DEFF Research Database (Denmark)

    Vigeant, Michelle C.; Wang, Lily M.; Rindel, Jens Holger

    2004-01-01

    considering reverberation time. However, for the three other parameters evaluated (sound pressure level, clarity index and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity......Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels...

  12. There are radiation sources out there!

    International Nuclear Information System (INIS)

    Bahran, M.Y.

    2001-01-01

    During the past few years we have been working in the area of the safety of radiation sources and radioactive materials. In this paper we summarize our findings and describe the recovery of an abandoned source. We call for further international co-operation in this area. In particular, we suggest an international system for the tagging and tracking of radioactive sources. (author)

  13. Radiation protection and the safety of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    These Safety Fundamentals cover the protection of human beings against ionizing radiation (gamma and X rays and alpha, beta and other particles that can induce ionization as they interact with biological materials), referred to herein subsequently as radiation, and the safety of sources that produce ionizing radiation. The Fundamentals do not apply to non-ionizing radiation such as microwave, ultraviolet, visible and infrared radiation. They do not apply either to the control of non-radiological aspects of health and safety. They are, however, part of the overall framework of health and safety

  14. Radiation sources and technical services

    International Nuclear Information System (INIS)

    Stonek, K.; Satorie, Z.; Vyskocil, I.

    1981-01-01

    Work is briefly described of the department for sealed sources production of the Institute, including leak testing and surface contamination of sealed sources. The department also provides technical services including the inspections of sealed sources used in medicine and geology and repair of damaged sources. It carries out research of the mechanical and thermal strength of sealed sources and of the possibility of reprocessing used 226 Ra sources. The despatch department is responsible for supplying the entire country with home and imported radionuclides. The department of technical services is responsible for testing imported radionuclides, assembling materials testing, industrial and medical irradiation devices, and for the collection and storage of low-level wastes on a national scale. (M.D.)

  15. Radiation Safety and Orphan Sources

    International Nuclear Information System (INIS)

    Janzekovic, H.; Krizman, M.

    2006-01-01

    The wide spread use of radioactive and particularly of nuclear materials which started in the last century very quickly also demonstrated negative sides. The external exposure and radiotoxicity of these materials could be easily used in a malevolent act. Due to the fact that these materials could not be detected without special equipment designed for that purpose, severe control over their use in all phases of a life cycle is required. An orphan source is a radioactive source which is not under regulatory control, either because it has never been under regulatory or because it has been abandoned, lost, misplaced, stolen or transferred without proper authorization. In the last ten years a few international conferences were dedicated to the improvement of the safety and security of radioactive sources. Three main tasks are focused, the maintenance of data bases related to events with orphan sources and the publications of such events, the preparation of recommendations and guidelines to national regulatory bodies in order to prevent and detect the events related to orphan sources as well as to develop the response strategies to radiological or nuclear emergency, appraisals of the national strategies of radioactive sources control. Concerning Slovenia, strengthening control over orphan sources in Slovenia started after the adoption of new legislation in 2002. It was carried out through several tasks with the aim to prevent orphan sources, as well as to identify the sources which could be potentially orphan sources. The comprehensive methodology was developed by the Slovenian nuclear safety administration (S.N.S.A.) based on international guidelines as well as on the study of national lesson learned cases. The methodology was developed and used in close cooperation with all parties involved, namely other regulatory authorities, police, customs, agency for radioactive waste management (A.R.A.O.), technical support organisations (T.S.O.), users of source, authorised

  16. Radiation Safety and Orphan Sources

    Energy Technology Data Exchange (ETDEWEB)

    Janzekovic, H.; Krizman, M. [Slovenian Nuclear Safety Administration, Ljubljana (Slovenia)

    2006-07-01

    The wide spread use of radioactive and particularly of nuclear materials which started in the last century very quickly also demonstrated negative sides. The external exposure and radiotoxicity of these materials could be easily used in a malevolent act. Due to the fact that these materials could not be detected without special equipment designed for that purpose, severe control over their use in all phases of a life cycle is required. An orphan source is a radioactive source which is not under regulatory control, either because it has never been under regulatory or because it has been abandoned, lost, misplaced, stolen or transferred without proper authorization. In the last ten years a few international conferences were dedicated to the improvement of the safety and security of radioactive sources. Three main tasks are focused, the maintenance of data bases related to events with orphan sources and the publications of such events, the preparation of recommendations and guidelines to national regulatory bodies in order to prevent and detect the events related to orphan sources as well as to develop the response strategies to radiological or nuclear emergency, appraisals of the national strategies of radioactive sources control. Concerning Slovenia, strengthening control over orphan sources in Slovenia started after the adoption of new legislation in 2002. It was carried out through several tasks with the aim to prevent orphan sources, as well as to identify the sources which could be potentially orphan sources. The comprehensive methodology was developed by the Slovenian nuclear safety administration (S.N.S.A.) based on international guidelines as well as on the study of national lesson learned cases. The methodology was developed and used in close cooperation with all parties involved, namely other regulatory authorities, police, customs, agency for radioactive waste management (A.R.A.O.), technical support organisations (T.S.O.), users of source, authorised

  17. ROSY - Rossendorf synchrotron radiation source

    International Nuclear Information System (INIS)

    Einfeld, D.; Matz, W.

    1993-11-01

    The electron energy of the storage ring will be 3 GeV and the emitted synchrotron radiation is in the hard X-ray region with a critical energy of the spectrum of E c =8,4 keV (λ c =0,14 nm). With a natural emittance of 28 π nm rad ROSY emits high brilliance radiation. Besides the radiation from bending magnets there will be the possibility for using radiation from wigglers and undulators. For the insertion devices 8 places are foreseen four of which are located in non-dispersion-free regions. The storage ring is of fourfold symmetry, has a circumference of 148 m and is designed in a modified FODO structure. An upgrade of ROSY with superconducting bending magnets in order to shift the spectrum to higher energy can easily be done. Part I contains the scientific case and a description of the planned use of the beam lines. Part II describes the design of the storage ring and its components in more detail. (orig.) [de

  18. Ionizing radiation sources. Ionizing radiation interaction with matter

    International Nuclear Information System (INIS)

    Popits, R.

    1976-01-01

    Fundamentals of nuclear physics are reviewed under the headings: obtaining of X-rays and their properties; modes of radioactive decay of natural or man-made radionuclides; radioactive neutron sources; nuclear fission as basis for devising nuclear reactors and weapons; thermonuclear reactions; cosmic radiation. Basic aspects of ionizing radiation interactions with matter are considered with regard to charged particles, photon radiation, and neutrons. (A.B.)

  19. Reproduction of nearby sources by imposing true interaural differences on a sound field control approach

    DEFF Research Database (Denmark)

    Badajoz, Javier; Chang, Ji-ho; Agerkvist, Finn T.

    2015-01-01

    In anechoic conditions, the Interaural Level Difference (ILD) is the most significant auditory cue to judge the distance to a sound source located within 1 m of the listener's head. This is due to the unique characteristics of a point source in its near field, which result in exceptionally high...... as Pressure Matching (PM), and a binaural control technique. While PM aims at reproducing the incident sound field, the objective of the binaural control technique is to ensure a correct reproduction of interaural differences. The combination of these two approaches gives rise to the following features: (i......, distance dependent ILDs. When reproducing the sound field of sources located near the head with line or circular arrays of loudspeakers, the reproduced ILDs are generally lower than expected, due to physical limitations. This study presents an approach that combines a sound field reproduction method, known...

  20. Improvements on the directional characteristics of a calibration sound source using the Boundary Element Method

    DEFF Research Database (Denmark)

    Henriquez, Vicente Cutanda; Barrera Figueroa, Salvador; Juhl, Peter Møller

    2008-01-01

    is of particular importance to achieve a sound field that reaches both microphones with the same level and that is sufficiently uniform at the microphone positions, in order to reduce the effect of misalignment. An existing sound source has been modeled using the Boundary Element Method, and the simulations have......The project Euromet-792 aims to investigate and improve methods for secondary free-field calibration of microphones. In this framework, the comparison method is being studied at DFM in relation to the more usual substitution method of microphone calibration. The design of the sound source...... been used to modify the source and make it suitable for this kind of calibration. It has been found that a central plug, already present in the device, can be re-shaped in such a way that makes the sound field on the microphone positions more uniform, even at rather high frequencies. Measurements have...

  1. The effects of viscosity on sound radiation near solid surfaces

    DEFF Research Database (Denmark)

    Morfey, C.L.; Sorokin, Sergey; Gabard, G.

    2012-01-01

    Although the acoustic analogy developed by Lighthill, Curle, and Ffowcs Williams and Hawkings for sound generation by unsteady flow past solid surfaces is formally exact, it has become accepted practice in aeroacoustics to use an approximate version in which viscous quadrupoles are neglected. Her...

  2. The utilization of radiation sources in Angola

    International Nuclear Information System (INIS)

    Lemos, P.C.D.

    2001-01-01

    The report describes the situation that Angola, which joined the IAEA in September 1999, is facing with the lack of an appropriate infrastructure for the control of radiation sources. It emphasizes the country's needs in technical assistance from the IAEA and other Member States for improving its regulatory infrastructure for radiation safety. (author)

  3. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

    -conversion medium, we demonstrate milliwatt-level, stable, and tunable Cherenkov radiation at visible wavelengths 580–630 nm, with pulse duration of sub-160-fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such an all-fiber Cherenkov radiation source is promising for practical applications in biophotonics...

  4. Management of Spent Radiation Source from Radiotherapy

    International Nuclear Information System (INIS)

    Aisyah

    2008-01-01

    Nowadays the use of radioactive source for both radiodiagnostic and radiotherapy in Indonesia hospital increases rapidly. Sealed source used in radiotherapy among others for brachytherapy, teletherapy, bone densitometry, whole blood irradiation and gamma knife (radiosurgery). In line with this, the waste of spent radiation sources will be generated in hospitals. Of course these spent radiation sources must be treated correctly in order to maintain the safety of both the public and the environment. According to the Act No. 10/1997, BATAN, in care of the Radioactive Waste Management Center is the national appointed agency for the management of radioactive waste. The option for waste management by hospitals needs to be expound, either by re-exporting to the supplier of origin, re-exporting to other supplier, re-use by other licensee or sending to the Radioactive Waste Management Center. Usually the waste sent by the hospitals to the center comprises of sealed radiation source of 60 Co, 137 Cs or 226 Ra. The management of spent radiation source in the center is carried out in several steps i.e. conditioning, temporary storage, and long-term storage (final disposal). The conditioning of non 226 Ra is carried out by placing the waste in a 200 litter drum shell, 950 or 350 litter concrete shells, depends on the activity and dimension of the spent radiation source. The conditioning of 226 Ra is carried out by encapsulating the waste in a stainless steel container for long-term storage shield which then placed in a 200 litter drum shell. The temporary storage of the conditioned spent radiation source is carried out by storing it in the center’s temporary storages, either low or medium activity waste. Finally, the conditioned spent radiation source is buried in a disposal facility. For medium half-life spent radiation source, the final disposal is burial it in a shallow-land disposal; mean while, for long half-life spent radiation source, the final disposal is burial it in

  5. Irradiation device using radiation sources

    International Nuclear Information System (INIS)

    Perraudin, Claude; Amarge, Edmond; Guiho, J.-P.; Horiot, J.-C.; Taniel, Gerard; Viel, Georges; Brethon, J.-P.

    1981-01-01

    The invention refers to an irradiation appliance making use of radioactive sources such as cobalt 60. This invention concerns an irradiation appliance delivering an easily adjustable irradiation beam in accurate dimensions and enabling the radioactive sources to be changed without making use of intricate manipulations at the very place where the appliance has to be used. This kind of appliance is employed in radiotherapy [fr

  6. Devices for obtaining information about radiation sources

    International Nuclear Information System (INIS)

    Tosswill, C.H.

    1981-01-01

    The invention provides a sensitive, fast high-resolution device for obtaining information about the distribution of gamma and X-radiation sources and provides a radiation detector useful in such a device. It comprises a slit collimator with a multiplicity of slits each with slit-defining walls of material and thickness to absorb beam components impinging on them. The slits extend further in one direction than the other. The detector for separately detecting beam components passing through the slits also provides data output signals. It comprises a plurality of radiation transducing portions which are not photoconductor elements each at the end of a slit. A positioner operates to change the transverse position of the slits and radiation transducing portions relative to the source, wherein each radiation transducing element is positioned within its respective slit between the slit defining walls. Full details and preferred embodiments are given. (U.K.)

  7. Radiation therapy sources, equipment and installations

    International Nuclear Information System (INIS)

    2011-03-01

    The safety code for Telegamma Therapy Equipment and Installations, (AERB/SC/MED-1) and safety code for Brachytherapy Sources, Equipment and Installations, (AERB/SC/MED-3) were issued by AERB in 1986 and 1988 respectively. These codes specified mandatory requirements for radiation therapy facilities, covering the entire spectrum of operations ranging from the setting up of a facility to its ultimate decommissioning, including procedures to be followed during emergency situations. The codes also stipulated requirements of personnel and their responsibilities. With the advent of new techniques and equipment such as 3D-conformal radiation therapy, intensity modulated radiation therapy, image guided radiation therapy, treatment planning system, stereotactic radiosurgery, stereotactic radiotherapy, portal imaging, integrated brachytherapy and endovascular brachytherapy during the last two decades, AERB desires that these codes be revised and merged into a single code titled Radiation Therapy Sources, Equipment, and Installations

  8. Security of radioactive sources in radiation facilities

    International Nuclear Information System (INIS)

    2011-03-01

    Safety codes and safety standards are formulated on the basis of internationally accepted safety criteria for design, construction and operation of specific equipment, systems, structures and components of nuclear and radiation facilities. Safety codes establish the objectives and set requirements that shall be fulfilled to provide adequate assurance for safety. Safety guides and guidelines elaborate various requirements and furnish approaches for their implementation. Safety manuals deal with specific topics and contain detailed scientific and technical information on the subject. These documents are prepared by experts in the relevant fields and are extensively reviewed by advisory committees of the Board before they are published. The documents are revised when necessary, in the light of experience and feedback from users as well as new developments in the field. In India, radiation sources are being widely used for societal benefits in industry, medical practices, research, training and agriculture. It has been reported from all over the world that unsecured radioactive sources caused serious radiological accidents involving radiation injuries and fatalities. Particular concern was expressed regarding radioactive sources that have become orphaned (not under regulatory control) or vulnerable (under weak regulatory control and about to be orphaned). There is a concern about safety and security of radioactive sources and hence the need of stringent regulatory control over the handling of the sources and their security. In view of this, this guide is prepared which gives provisions necessary to safeguard radiation installations against theft of radioactive sources and other malevolent acts that may result in radiological consequences. It is, therefore, required that the radiation sources are used safely and managed securely by only authorised personnel. This guide is intended to be used by users of radiation sources in developing the necessary security plan for

  9. Effect of a serrated trailing edge on sound radiation from nearby quadrupoles.

    Science.gov (United States)

    Karimi, Mahmoud; Croaker, Paul; Kinns, Roger; Kessissoglou, Nicole

    2017-05-01

    A periodic boundary element technique is implemented to study the noise reduction capability of a plate with a serrated trailing edge under quadrupole excitation. It is assumed for this purpose that the quadrupole source tensor is independent of the trailing edge configuration and that the effect of the trailing edge shape is to modify sound radiation from prescribed boundary layer sources. The flat plate is modelled as a continuous structure with a finite repetition of small spanwise segments. The matrix equation formulated by the periodic boundary element method for this 3D acoustic scattering problem is represented as a block Toeplitz matrix. The discrete Fourier transform is employed in an iterative algorithm to solve the block Toeplitz system. The noise reduction mechanism for a serrated trailing edge in the near field is investigated by comparing contour plots obtained from each component of the quadrupole for unserrated and serrated trailing edge plate models. The noise reduction due to the serrated trailing edge is also examined as a function of the source location.

  10. Regulatory control of radiation sources. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    The basic requirements for the protection of persons against exposure to ionizing radiation and for the safety of radiation sources were established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards), jointly sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Atomic Energy Agency (IAEA), the International Labour Organization (ILO), the OECD Nuclear Energy Agency (OECD/ NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO) (the Sponsoring Organizations). The application of the Basic Safety Standards is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities for radiation protection and safety. Requirements relating to the legal and governmental infrastructure for the safety of nuclear facilities and sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material are established in the Safety Requirements on Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, Safety Standards Series No. GS-R-1. This Safety Guide, which is jointly sponsored by the FAO, the IAEA, the International Labour Office, the PAHO and the WHO, gives detailed guidance on the key elements for the organization and operation of a national regulatory infrastructure for radiation safety, with particular reference to the functions of the national regulatory body that are necessary to ensure the implementation of the Basic Safety Standards. The Safety Guide is based technically on material first published in IAEA-TECDOC-10671, which was jointly sponsored by the FAO, the IAEA, the OECD/NEA, the PAHO and the WHO. The requirements established in GS-R-1 have been taken into account. The Safety Guide is oriented towards national

  11. Improving the efficiency of deconvolution algorithms for sound source localization

    DEFF Research Database (Denmark)

    Lylloff, Oliver Ackermann; Fernandez Grande, Efren; Agerkvist, Finn T.

    2015-01-01

    of the unknown acoustic source distribution and the beamformer's response to a point source, i.e., point-spread function. A significant limitation of deconvolution is, however, an additional computational effort compared to beamforming. In this paper, computationally efficient deconvolution algorithms...

  12. Sound radiation modes of cylindrical surfaces and their application to vibro-acoustics analysis of cylindrical shells

    Science.gov (United States)

    Sun, Yao; Yang, Tiejun; Chen, Yuehua

    2018-06-01

    In this paper, sound radiation modes of baffled cylinders have been derived by constructing the radiation resistance matrix analytically. By examining the characteristics of sound radiation modes, it is found that radiation coefficient of each radiation mode increases gradually with the increase of frequency while modal shapes of sound radiation modes of cylindrical shells show a weak dependence upon frequency. Based on understandings on sound radiation modes, vibro-acoustics behaviors of cylindrical shells have been analyzed. The vibration responses of cylindrical shells are described by modified Fourier series expansions and solved by Rayleigh-Ritz method involving Flügge shell theory. Then radiation efficiency of a resonance has been determined by examining whether the vibration pattern is in correspondence with a sound radiation mode possessing great radiation efficiency. Furthermore, effects of thickness and boundary conditions on sound radiation of cylindrical shells have been investigated. It is found that radiation efficiency of thicker shells is greater than thinner shells while shells with a clamped boundary constraint radiate sound more efficiently than simply supported shells under thin shell assumption.

  13. Maximum likelihood approach to “informed” Sound Source Localization for Hearing Aid applications

    DEFF Research Database (Denmark)

    Farmani, Mojtaba; Pedersen, Michael Syskind; Tan, Zheng-Hua

    2015-01-01

    Most state-of-the-art Sound Source Localization (SSL) algorithms have been proposed for applications which are "uninformed'' about the target sound content; however, utilizing a wireless microphone worn by a target talker, enables recent Hearing Aid Systems (HASs) to access to an almost noise......-free sound signal of the target talker at the HAS via the wireless connection. Therefore, in this paper, we propose a maximum likelihood (ML) approach, which we call MLSSL, to estimate the Direction of Arrival (DoA) of the target signal given access to the target signal content. Compared with other "informed...

  14. Ionization detector with improved radiation source

    International Nuclear Information System (INIS)

    Solomon, E.F.

    1977-01-01

    The detector comprises a chamber having at least one radiation source disposed therein. The chamber includes spaced collector plates which form a part of a detection circuit for sensing changes in the ionization current in the chamber. The radiation source in one embodiment is in the form of a wound wire or ribbon suitably supported in the chamber and preferably a source of beta particles. The chamber may also include an adjustable electrode and the source may function as an adjustable current source by forming the wire or ribbon in an eliptical shape and rotating the structure. In another embodiment the source has a random shape and is homogeneously disposed in the chamber. 13 claims, 5 drawing figures

  15. Exposures to natural radiation sources. Annex B

    International Nuclear Information System (INIS)

    1982-01-01

    The assessment of the radiation doses from natural sources in humans is presented. Both external sources of extraterrestrial origin (cosmic rays) and of terrestrial origin, and internal sources, comprising the naturally-occurring radionuclides which are taken into the human body, are discussed. This Annex is to a large extent a summary of Annex B of the 1977 report of the Committee. The doses due to the radon isotopes and to their short-lived decay products are briefly reviewed.

  16. Safe management of spent radiation source

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Sugiura, Nobuyuki; Valdezco, E.M.; Choi, Kwang-Sub

    2003-01-01

    Presented are 8 investigation reports concerning the safe management of spent radiation source (SRS) during the current 2 years. Four reports from Japan are: Scheme for SRS management (approach and present status of the SRS management and consideration toward solving problems); Current International Atomic Energy Agency (IAEA) activities related to safety of radiation sources (Chronology of action plan development, Outline of revised action plan, and Asian regional activities); Current status of SRS management in Japan (Regulation system, Obligations of licensed users, Regulatory system on sealed sources, Status in the incidents on sources occurred, Incident of source loss, and Incidents of orphan sources); and SRS management system in Japan (Current status of using of sealed sources, collection system of SRS-Japan Radioisotope Association (JRIA) services, and Disposal of SRS). Four reports from the Asian countries also concern the current statuses of SRS management in the Philippine (Radioactive waste sources, Waste management strategies, Conditioning of Ra sources, Ra project action plan, as low as reasonably achievable (ALARA) program, Dose assessment, Regulations on radioactive waste, Action plan on the safety and security of sources, IAEA Regional Demonstration Centers, and sitting studies for a near surface disposal facility); Thailand (Current status of using sealed sources, Inventory of SRS, and Current topics of SRS management); Indonesia (Principles of management of radiation sources, Legislative framework of SRS management practices, Regulatory on SRS, management of sealed SRS, management hurdles, and reported incidents); and Korea (Regulatory frame work, Collection systems of SRS, Radioisotope waste generation, Radiation exposure incident, and Scrap monitoring system). (N.I.)

  17. Sound power emitted by a pure-tone source in a reverberation room

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Molares, Alfonso Rodriguez

    2009-01-01

    Energy considerations are of enormous practical importance in acoustics. In "energy acoustics," sources of noise are described in terms of the sound power they emit, the underlying assumption being that this property is independent of the particular environment where the sources are placed. Howev...

  18. The safe use of radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    As a means of promoting safety in the use of radiation sources, as well as encouraging consistency in regulatory control, the IAEA has from time to time organized training courses with the co-operation of Member State governments and organizations, to inform individuals from developing countries with appropriate responsibilities on the provisions for the safe use and regulation of radiation sources. Three such courses on the safe use of radiation sources have been held in both the USA, with the co-operation of the United States Government, and in Dublin, Ireland, with the co-operation of the Irish Government. The Training Course on the Safe Use and Regulation of Radiation Sources has been successfully given to over 77 participants from over 30 countries during the last years. The course is aimed at providing a basis of radiation protection knowledge in all aspects of the uses of radiation and of radiation sources that are used today. It is the intention of this course to provide a systematic enhancement of radioisotope safety in countries with developing radiological programmes through a core group of national authorities. The IAEA's training programmes provide an excellent opportunity for direct contact with lecturers that have extensive experience in resolving issues faced by developing countries and in providing guidance documents useful in addressing their problems. This document uses this collective experience and provides valuable technical information regarding the safety aspects of the uses not only of sealed and unsealed sources of radiation, but also for those machines that produce ionizing radiation. The first of these training courses, 'Safety and Regulation of Unsealed Sources' was held in Dublin, Ireland, June through July 1989 with the co-operation of the Nuclear Energy Board and Trinity College. This was an interregional training course, the participants came from all over the world. The second and third interregional courses, 'Safety and Regulation

  19. The safe use of radiation sources

    International Nuclear Information System (INIS)

    1995-01-01

    As a means of promoting safety in the use of radiation sources, as well as encouraging consistency in regulatory control, the IAEA has from time to time organized training courses with the co-operation of Member State governments and organizations, to inform individuals from developing countries with appropriate responsibilities on the provisions for the safe use and regulation of radiation sources. Three such courses on the safe use of radiation sources have been held in both the USA, with the co-operation of the United States Government, and in Dublin, Ireland, with the co-operation of the Irish Government. The Training Course on the Safe Use and Regulation of Radiation Sources has been successfully given to over 77 participants from over 30 countries during the last years. The course is aimed at providing a basis of radiation protection knowledge in all aspects of the uses of radiation and of radiation sources that are used today. It is the intention of this course to provide a systematic enhancement of radioisotope safety in countries with developing radiological programmes through a core group of national authorities. The IAEA's training programmes provide an excellent opportunity for direct contact with lecturers that have extensive experience in resolving issues faced by developing countries and in providing guidance documents useful in addressing their problems. This document uses this collective experience and provides valuable technical information regarding the safety aspects of the uses not only of sealed and unsealed sources of radiation, but also for those machines that produce ionizing radiation. The first of these training courses, 'Safety and Regulation of Unsealed Sources' was held in Dublin, Ireland, June through July 1989 with the co-operation of the Nuclear Energy Board and Trinity College. This was an interregional training course, the participants came from all over the world. The second and third interregional courses, 'Safety and Regulation

  20. X radiation sources based on accelerators

    International Nuclear Information System (INIS)

    Couprie, M.E.; Filhol, J.M.

    2008-01-01

    Light sources based on accelerators aim at producing very high brilliance coherent radiation, tunable from the infrared to X-ray range, with picosecond or femtosecond light pulses. The first synchrotron light sources were built around storage rings in which a large number of relativistic electrons produce 'synchrotron radiation' when their trajectory is subjected to a magnetic field, either in bending magnets or in specific insertion devices (undulators), made of an alternating series of magnets, allowing the number of curvatures to be increased and the radiation to be reinforced. These 'synchrotron radiation' storage rings are now used worldwide (there are more than thirty), and they simultaneously distribute their radiation to several tens of users around the storage ring. The most effective installations in term of brilliance are the so-called third generation synchrotron radiation light sources. The radiation produced presents pulse durations of the order of a few tens of ps, at a high rate (of the order of MHz); it is tunable over a large range, depending on the magnetic field and the electron beam energy and its polarisation is adjustable (in the V-UV-soft-X range). Generally, a very precise spectral selection is made by the users with a monochromator. The single pass linear accelerators can produce very short electron bunches (around 100 fs). The beam of very high electronic density is sent into successive undulator modules, reinforcing the radiation's longitudinal coherence, produced according to a Free Electron Laser (FEL) scheme by the interaction between the electron bunch and a light wave. The very high peak brilliance justifies their designation as fourth generation sources. The number of users is smaller because an electron pulse produces a radiation burst towards only one beamline. Energy Recovery Linacs (ERL) let the beam pass several times in the accelerator structures either to recover the energy or to accelerate the electrons during several turns

  1. Cosmical sources of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kuchowicz, B [Warsaw Univ. (Poland)

    1974-01-01

    A brief historical outline of the X-ray and ..gamma..-ray astronomies is given first, then a summary of the recent status of X-ray astronomy follows. Further chapters include information on ..gamma..-ray sources in the solar system, in our Galaxy, and beyond it. In discussing linear gamma spectra attention is paid to the possibility of studying explosive nucleo-synthesis by observation of gamma lines from supernova remnants, etc. Questions of the isotropic gamma background are discussed at the end of the survey.

  2. A method for estimating the orientation of a directional sound source from source directivity and multi-microphone recordings: principles and application

    DEFF Research Database (Denmark)

    Guarato, Francesco; Jakobsen, Lasse; Vanderelst, Dieter

    2011-01-01

    Taking into account directivity of real sound sources makes it possible to try solving an interesting and biologically relevant problem: estimating the orientation in three-dimensional space of a directional sound source. The source, of known directivity, produces a broadband signal (in the ultra......Taking into account directivity of real sound sources makes it possible to try solving an interesting and biologically relevant problem: estimating the orientation in three-dimensional space of a directional sound source. The source, of known directivity, produces a broadband signal (in...

  3. Devices for obtaining information about radiation sources

    International Nuclear Information System (INIS)

    Tosswill, C.H.

    1981-01-01

    The invention provides a sensitive, fast, high-resolution device for obtaining information about the distribution of gamma and X-radiation sources and provides a radiation detector useful in such a device. It comprises a slit collimator with a multiplicity of slits each with slit-defining walls of material and thickness to absorb beam components impinging on them. The slits extend further in one transverse direction than the other. The detector for separately detecting beam components passing through the slits also provides data output signals. It comprises a plurality of radiation transducing portions, each at the end of a slit. A positioner changes the transverse position of the slits and radiation transducer (a photoconductor) relative to the source. Applications are in nuclear medicine and industry. Full details and preferred embodiments are given. (U.K.)

  4. Sound source reconstruction using inverse boundary element calculations

    DEFF Research Database (Denmark)

    Schuhmacher, Andreas; Hald, Jørgen; Rasmussen, Karsten Bo

    2003-01-01

    Whereas standard boundary element calculations focus on the forward problem of computing the radiated acoustic field from a vibrating structure, the aim in this work is to reverse the process, i.e., to determine vibration from acoustic field data. This inverse problem is brought on a form suited ...... it is demonstrated that the L-curve criterion is robust with respect to the errors in a real measurement situation. In particular, it is shown that the L-curve criterion is superior to the more conventional generalized cross-validation (GCV) approach for the present tire noise studies....

  5. A novel method for direct localized sound speed measurement using the virtual source paradigm

    DEFF Research Database (Denmark)

    Byram, Brett; Trahey, Gregg E.; Jensen, Jørgen Arendt

    2007-01-01

    ) mediums. The inhomogeneous mediums were arranged as an oil layer, one 6 mm thick and the other 11 mm thick, on top of a water layer. To complement the phantom studies, sources of error for spatial registration of virtual detectors were simulated. The sources of error presented here are multiple sound...... registered virtual detector. Between a pair of registered virtual detectors a spherical wave is propagated. By beamforming the received data the time of flight between the two virtual sources can be calculated. From this information the local sound speed can be estimated. Validation of the estimator used...... both phantom and simulation results. The phantom consisted of two wire targets located near the transducer's axis at depths of 17 and 28 mm. Using this phantom the sound speed between the wires was measured for a homogeneous (water) medium and for two inhomogeneous (DB-grade castor oil and water...

  6. Low sound level source path contribution on a HVAC

    NARCIS (Netherlands)

    Bree, H.E. de; Basten, T.G.H.

    2008-01-01

    For compliance test purposes, the noise level of a HVAC is usually measured with a pressure microphone positioned at a certain distance. This measurement is normally performed in an anechoic room. However, this method doesn't provide the engineer any insight on what noise sources do contribute to

  7. MODEL OF A PERSONWALKING AS A STRUCTURE BORNE SOUND SOURCE

    DEFF Research Database (Denmark)

    Lievens, Matthias; Brunskog, Jonas

    2007-01-01

    has to be considered and the contact history must be integrated in the model. This is complicated by the fact that nonlinearities occur at different stages in the system either on the source or receiver side. ot only lightweight structures but also soft floor coverings would benefit from an accurate...

  8. A study investigating sound sources and noise levels in neonatal ...

    African Journals Online (AJOL)

    Background. Exposure to noise in the neonatal intensive care unit (NICU) has the potential to affect neonatal auditory development, sleep patterns and physiological stability, thus impacting on developmental progress. Objectives. This study aimed to identify noise sources in three NICUs in Johannesburg, South Africa, and ...

  9. Assessment of risk from radiation sources

    International Nuclear Information System (INIS)

    Subbaratnam, T.; Madhvanath, U.; Somasundaram, S.

    1976-01-01

    Assessment of risk from exposure to ionizing radiations from man-made radiation sources and nuclear installations has to be viewed from three aspects, namely, dose-effect relationship (genetic and somatic) for humans, calculation of doses or dose-commitments to population groups, assessment of risk to radiation workers and the population at large from the current levels of exposure from nuclear industry and comparison of risk estimates with other industries in a modern society. These aspects are discussed in brief. On the basis of available data, it is shown that estimated incidence of genetic diseases and cancers due to exposure of population to radiation from nuclear industry is negligible in comparison with their natural incidence, and radiation risks to the workers in nuclear industry are much lower than the risks in other occupations. (M.G.B.)

  10. Identification of impact force acting on composite laminated plates using the radiated sound measured with microphones

    Science.gov (United States)

    Atobe, Satoshi; Nonami, Shunsuke; Hu, Ning; Fukunaga, Hisao

    2017-09-01

    Foreign object impact events are serious threats to composite laminates because impact damage leads to significant degradation of the mechanical properties of the structure. Identification of the location and force history of the impact that was applied to the structure can provide useful information for assessing the structural integrity. This study proposes a method for identifying impact forces acting on CFRP (carbon fiber reinforced plastic) laminated plates on the basis of the sound radiated from the impacted structure. Identification of the impact location and force history is performed using the sound pressure measured with microphones. To devise a method for identifying the impact location from the difference in the arrival times of the sound wave detected with the microphones, the propagation path of the sound wave from the impacted point to the sensor is examined. For the identification of the force history, an experimentally constructed transfer matrix is employed to relate the force history to the corresponding sound pressure. To verify the validity of the proposed method, impact tests are conducted by using a CFRP cross-ply laminate as the specimen, and an impulse hammer as the impactor. The experimental results confirm the validity of the present method for identifying the impact location from the arrival time of the sound wave detected with the microphones. Moreover, the results of force history identification show the feasibility of identifying the force history accurately from the measured sound pressure using the experimental transfer matrix.

  11. Plasma x-ray radiation source.

    Science.gov (United States)

    Popkov, N F; Kargin, V I; Ryaslov, E A; Pikar', A S

    1995-01-01

    This paper gives the results of studies on a plasma x-ray source, which enables one to obtain a 2.5-krad radiation dose per pulse over an area of 100 cm2 in the quantum energy range from 20 to 500 keV. Pulse duration is 100 ns. Spectral radiation distributions from a diode under various operation conditions of a plasma are obtained. A Marx generator served as an initial energy source of 120 kJ with a discharge time of T/4 = 10-6 s. A short electromagnetic pulse (10-7 s) was shaped using plasma erosion opening switches.

  12. Occupational exposure to natural sources of radiation

    International Nuclear Information System (INIS)

    Ortiz, T.; Sciocchetti, G.; Rannou, A.

    1993-01-01

    The most important natural sources of radiation are analyzed. The situation in France, Italy, and Spain concerning protection against natural radiation is described, including the identification of sources, and defined practices, organizations charged of national surveys and the responsibility of regulatory bodies and the role of operating management. The activities of the international organizations (ICRP, CEC and IAEA) are presented and discussed, and existing actions toward harmonization in the CEC, IAEA and other international programs is also discussed. (R.P.) 23 refs., 2 tabs

  13. Sound transmission analysis of plate structures using the finite element method and elementary radiator approach with radiator error index

    DEFF Research Database (Denmark)

    Jung, Jaesoon; Kook, Junghwan; Goo, Seongyeol

    2017-01-01

    combines the FEM and Elementary Radiator Approach (ERA) is proposed. The FE-ERA method analyzes the vibrational response of the plate structure excited by incident sound using FEM and then computes the transmitted acoustic pressure from the vibrating plate using ERA. In order to improve the accuracy...... and efficiency of the FE-ERA method, a novel criterion for the optimal number of elementary radiators is proposed. The criterion is based on the radiator error index that is derived to estimate the accuracy of the computation with used number of radiators. Using the proposed criterion a radiator selection method...... is presented for determining the optimum number of radiators. The presented radiator selection method and the FE-ERA method are combined to improve the computational accuracy and efficiency. Several numerical examples that have been rarely addressed in previous studies, are presented with the proposed method...

  14. Photon acceleration-based radiation sources

    International Nuclear Information System (INIS)

    Hoffman, J. R.; Muggli, P.; Katsouleas, T.; Mori, W. B.; Joshi, C.

    1999-01-01

    The acceleration and deceleration of photons in a plasma provides the means for a series of new radiation sources. Previous work on a DC to AC Radiation Converter (DARC source) has shown variable acceleration of photons having zero frequency (i.e., an electrostatic field) to between 6 and 100 GHz (1-3). These sources all had poor guiding characteristics resulting in poor power coupling from the source to the load. Continuing research has identified a novel way to integrate the DARC source into a waveguide. The so called ''pin structure'' uses stainless steel pins inserted through the narrow side of an X band waveguide to form the electrostatic field pattern (k≠0, ω=0). The pins are spaced such that the absorption band resulting from this additional periodic structure is outside of the X band range (8-12 GHz), in which the normal waveguide characteristics are left unchanged. The power of this X band source is predicted theoretically to scale quadratically with the pin bias voltage as -800 W/(kV) 2 and have a pulse width of -1 ns. Cold tests and experimental results are presented. Applications for a high power, short pulse radiation source extends to the areas of landmine detection, improved radar resolution, and experimental investigations of molecular systems

  15. On-axis and far-field sound radiation from resilient flat and dome-shaped radiators

    NARCIS (Netherlands)

    Aarts, R.M.; Janssen, A.J.E.M.

    2009-01-01

    On-axis and far-field series expansions are developed for the sound pressure due to an arbitrary, circular symmetric velocity distribution on a flat radiator in an infinite baffle. These expansions are obtained by expanding the velocity distributions in terms of orthogonal polynomials

  16. Radiation Sources Working Group Summary Report

    International Nuclear Information System (INIS)

    Fazio, Michael V.

    1999-01-01

    The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, component technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigarion, and phenomena that impact source design such as fatigue in resonant structures due to pulsed RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations

  17. Radiation Sources Working Group Summary Report

    International Nuclear Information System (INIS)

    Fazio, M.V.

    1999-01-01

    The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, component technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigarion, and phenomena that impact source design such as fatigue in resonant structures due to pulsed RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations. copyright 1999 American Institute of Physics

  18. Differences in directional sound source behavior and perception between assorted computer room models

    DEFF Research Database (Denmark)

    Vigeant, M. C.; Wang, L. M.; Rindel, Jens Holger

    2004-01-01

    time. However, for the three other parameters evaluated (sound-pressure level, clarity index, and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity when using computer......Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels...

  19. Radiation measurement practice for understanding statistical fluctuation of radiation count using natural radiation sources

    International Nuclear Information System (INIS)

    Kawano, Takao

    2014-01-01

    It is known that radiation is detected at random and the radiation counts fluctuate statistically. In the present study, a radiation measurement experiment was performed to understand the randomness and statistical fluctuation of radiation counts. In the measurement, three natural radiation sources were used. The sources were fabricated from potassium chloride chemicals, chemical fertilizers and kelps. These materials contain naturally occurring potassium-40 that is a radionuclide. From high schools, junior high schools and elementary schools, nine teachers participated to the radiation measurement experiment. Each participant measured the 1-min integration counts of radiation five times using GM survey meters, and 45 sets of data were obtained for the respective natural radiation sources. It was found that the frequency of occurrence of radiation counts was distributed according to a Gaussian distribution curve, although the obtained 45 data sets of radiation counts superficially looked to be fluctuating meaninglessly. (author)

  20. Sustainably Sourced, Thermally Resistant, Radiation Hard Biopolymer

    Science.gov (United States)

    Pugel, Diane

    2011-01-01

    This material represents a breakthrough in the production, manufacturing, and application of thermal protection system (TPS) materials and radiation shielding, as this represents the first effort to develop a non-metallic, non-ceramic, biomaterial-based, sustainable TPS with the capability to also act as radiation shielding. Until now, the standing philosophy for radiation shielding involved carrying the shielding at liftoff or utilizing onboard water sources. This shielding material could be grown onboard and applied as needed prior to different radiation landscapes (commonly seen during missions involving gravitational assists). The material is a bioplastic material. Bioplastics are any combination of a biopolymer and a plasticizer. In this case, the biopolymer is a starch-based material and a commonly accessible plasticizer. Starch molecules are composed of two major polymers: amylase and amylopectin. The biopolymer phenolic compounds are common to the ablative thermal protection system family of materials. With similar constituents come similar chemical ablation processes, with the potential to have comparable, if not better, ablation characteristics. It can also be used as a flame-resistant barrier for commercial applications in buildings, homes, cars, and heater firewall material. The biopolymer is observed to undergo chemical transformations (oxidative and structural degradation) at radiation doses that are 1,000 times the maximum dose of an unmanned mission (10-25 Mrad), indicating that it would be a viable candidate for robust radiation shielding. As a comparison, the total integrated radiation dose for a three-year manned mission to Mars is 0.1 krad, far below the radiation limit at which starch molecules degrade. For electron radiation, the biopolymer starches show minimal deterioration when exposed to energies greater than 180 keV. This flame-resistant, thermal-insulating material is non-hazardous and may be sustainably sourced. It poses no hazardous

  1. 76 FR 6692 - Radiation Sources on Army Land

    Science.gov (United States)

    2011-02-08

    ... possession of ionizing radiation sources by non-Army entities (including their civilian contractors) on an... Radiation Permit (ARP) from the garrison commander to use, store, or possess ionizing radiation sources on an Army installation. For the purpose of this rule, ``ionizing radiation source'' means any source...

  2. Acoustic holography for piston sound radiation with non-uniform velocity profiles

    NARCIS (Netherlands)

    Aarts, R.M.; Janssen, A.J.E.M.

    2010-01-01

    The theory of orthogonal (Zernike) expansions of functions on a disk, as used in the diffraction theory of optical aberrations, is applied to obtain (semi-) analytical results for the radiation of sound due to a non-uniformly moving, baffled, circular piston. For this particular case, a scheme for

  3. Synchrotron radiation sources in the Soviet Union

    International Nuclear Information System (INIS)

    Kapitza, S.P.

    1987-01-01

    Synchrotron radiation (SR) is now recognized to be an important instrument for experimental work in many fields of science. Recently the application of SR in medicine and industry, especially as a light source for microelectronics production have been demonstrated. Thus the development of SR sources has now grown to become a significant and independent dimension for accelerator research and technology. This article describes SR work in the Soviet Union

  4. The Reduction of Vertical Interchannel Crosstalk: The Analysis of Localisation Thresholds for Natural Sound Sources

    Directory of Open Access Journals (Sweden)

    Rory Wallis

    2017-03-01

    Full Text Available In subjective listening tests, natural sound sources were presented to subjects as vertically-oriented phantom images from two layers of loudspeakers, ‘height’ and ‘main’. Subjects were required to reduce the amplitude of the height layer until the position of the resultant sound source matched that of the same source presented from the main layer only (the localisation threshold. Delays of 0, 1 and 10 ms were applied to the height layer with respect to the main, with vertical stereophonic and quadraphonic conditions being tested. The results of the study showed that the localisation thresholds obtained were not significantly affected by sound source or presentation method. Instead, the only variable whose effect was significant was interchannel time difference (ICTD. For ICTD of 0 ms, the median threshold was −9.5 dB, which was significantly lower than the −7 dB found for both 1 and 10 ms. The results of the study have implications both for the recording of sound sources for three-dimensional (3D audio reproduction formats and also for the rendering of 3D images.

  5. Auralization of airborne sound insulation including the influence of source room

    DEFF Research Database (Denmark)

    Rindel, Jens Holger

    2006-01-01

    The paper describes a simple and acoustically accurate method for the auralization of airborne sound insulation between two rooms by means of a room acoustic simulation software (ODEON). The method makes use of a frequency independent transparency of the transmitting surface combined...... with a frequency dependent power setting of the source in the source room. The acoustic properties in terms of volume and reverberation time as well as the area of the transmitting surface are all included in the simulation. The user only has to select the position of the source in the source room and the receiver...... of the transmitting surface is used for the simulation of sound transmission. Also the reduced clarity of the auralization due to the reverberance of the source room is inherent in the method. Currently the method is restricted to transmission loss data in octave bands....

  6. Radiation effects concerns at a spallation source

    International Nuclear Information System (INIS)

    Sommer, W.F.

    1990-01-01

    Materials used at spallation neutron sources are exposed to energetic particle and photon radiation. Mechanical and physical properties of these materials are altered; radiation damage on the atomic scale leads to radiation effects on the macroscopic scale. Most notable among mechanical-property radiation effects in metals and metal alloys are changes in tensile strength and ductility, changes in rupture strength, dimensional stability and volumetric swelling, and dimensional changes due to stress-induced creep. Physical properties such as electrical resistivity also are altered. The fission-reactor community has accumulated a good deal of data on material radiation effects. However, when the incident particle energy exceeds 50 MeV or so, a new form of radiation damage ensues; spallation reactions lead to more energetic atom recoils and the subsequent temporal and spatial distribution of point defects is much different from that due to a fission-reactor environment. In addition, spallation reactions cause atomic transmutations with these new atoms representing an impurity in the metal. The higher-energy case is of interest at spallation sources; limited detailed data exist for material performance in this environment. 35 refs., 13 figs., 1 tab

  7. Stabilized platform for tethered balloon soundings of broadband long- and short-wave radiation

    International Nuclear Information System (INIS)

    Alzheimer, J.M.; Anderson, G.A.; Whiteman, C.D.

    1993-01-01

    Changes in the composition of trace gases in the earth's atmosphere have been reported by many observers, and a general concern has been expressed regarding possible changes to the earth's climate that may be caused by radiatively active gases introduced into the earth's atmosphere by man's activities. Radiatively active trace gases produce temperature changes in the earth's atmosphere through changes in radiative flux divergence. Our knowledge of and means of measuring radiative flux divergence is very limited. A few observations of vertical radiative flux divergences have been reported from aircraft from radiometersondes from towers and from large tethered balloons. These measurement techniques suffers from one or more drawbacks, including shallow sounding depths (towers), high cost (aircraft), complicated logistics (large tethered balloons), and limitation to nighttime hours (radiometersondes). Changes in radiative flux divergence caused by anthropogenic trace gases are expected to be quite small, and will be difficult to measure with existing broadband radiative flux instruments. The emphasis of present research in global climate change is thus being focused on improving radiative transfer algorithms in global climate models. The radiative parameterizations in these models are at an early stage of development and information is needed regarding their performance, especially in cloudy conditions. The impetus for the research reported in this paper is the need for a device that can supplement existing means of measuring vertical profiles of long- and short-wave irradiance and radiative flux divergence. We have designed a small tethered-balloon-based system that can make radiometric soundings through the atmospheric boundary layer. This paper discusses the concept, the design considerations, and the design and construction of this sounding system. The performance of the system will be tested in a series of balloon flights scheduled for the fall and winter of 1992

  8. Trade and transport of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    The guide specifies the obligations pertaining to the trade in and transport of radiation sources and other matters to be taken into account in safety supervision. It also specifies obligations and procedures relating to transfrontier movements of radioactive waste contained in the EU Council Directive 92/3/Euratom. (7 refs.)

  9. Optimization of industrial processes using radiation sources

    International Nuclear Information System (INIS)

    Salles, Claudio G.; Silva Filho, Edmundo D. da; Toribio, Norberto M.; Gandara, Leonardo A.

    1996-01-01

    Aiming the enhancement of the staff protection against radiation in operational areas, the SAMARCO Mineracao S.A. proceeded a reevaluation and analysis of the real necessity of the densimeters/radioactive sources in the operational area, and also the development of an alternative control process for measurement the ore pulp, and introduced of the advanced equipment for sample chemical analysis

  10. Radiation as a source of risk

    International Nuclear Information System (INIS)

    Katoh, Kazuaki

    1999-01-01

    Essence and nature of ionizing radiation as a source of risk are reviewed. Following to the appeal of necessity and importance of campaign for enlightening risk management, of individual and of society, background knowledge and information helpful to the promotion and discussion are summarized, also. (author)

  11. Underdense radiation sources: Moving towards longer wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Back, C.A.; Kilkenny, J.D. [General Atomics, San Diego, California (United States); Seely, J.F.; Weaver, J.L. [Naval Research Laboratory, Washington, DC (United States); Feldman, U. [Artep Inc., Ellicott City, MD (United States); Tommasini, R.; Glendinning, S.G.; Chung, H.K.; Rosen, M.; Lee, R.W.; Scott, H.A. [Lawrence Livermore National Laboratory, California (United States); Tillack, M. [U. C. San Diego, La Jolla, CA (United States)

    2006-06-15

    Underdense radiation sources have been developed to provide efficient laboratory multi-keV radiation sources for radiography and radiation hardening studies. In these plasmas laser absorption by inverse Bremsstrahlung leads to high x-ray conversion efficiency because of efficient ionization of the low density aerogel or gas targets. Now we performing experiments in the soft x-ray energy regime where the atomic physics models are much more complicated. In recent experiments at the NIKE laser, we have irradiated a Ti-doped SiO{sub 2} aerogel with up to 1650 J of 248 nm wavelength light. The absolute Ti L-shell emission in the 200-800 eV range is measured with a diagnostic that uses a transmission grating coupled to Si photodiodes. We will give an overview of the temporally-resolved absolutely calibrated spectra obtained over a range of conditions. (authors)

  12. Underdense radiation sources: Moving towards longer wavelengths

    International Nuclear Information System (INIS)

    Back, C.A.; Kilkenny, J.D.; Seely, J.F.; Weaver, J.L.; Feldman, U.; Tommasini, R.; Glendinning, S.G.; Chung, H.K.; Rosen, M.; Lee, R.W.; Scott, H.A.; Tillack, M.

    2006-01-01

    Underdense radiation sources have been developed to provide efficient laboratory multi-keV radiation sources for radiography and radiation hardening studies. In these plasmas laser absorption by inverse Bremsstrahlung leads to high x-ray conversion efficiency because of efficient ionization of the low density aerogel or gas targets. Now we performing experiments in the soft x-ray energy regime where the atomic physics models are much more complicated. In recent experiments at the NIKE laser, we have irradiated a Ti-doped SiO 2 aerogel with up to 1650 J of 248 nm wavelength light. The absolute Ti L-shell emission in the 200-800 eV range is measured with a diagnostic that uses a transmission grating coupled to Si photodiodes. We will give an overview of the temporally-resolved absolutely calibrated spectra obtained over a range of conditions. (authors)

  13. Guidelines for testing sealed radiation sources

    International Nuclear Information System (INIS)

    1989-01-01

    These guidelines are based on article 16(1) of the Ordinance on the Implementation of Atomic Safety and Radiation Protection dated 11 October 1984 (VOAS), in connection with article 36 of the Executory Provision to the VOAS, of 11 October 1984. They apply to the testing of sealed sources to verify their intactness, tightness and non-contamination as well as observance of their fixed service time. The type, scope and intervals of testing as well as the evaluation of test results are determined. These guidelines also apply to the testing of radiation sources forming part of radiation equipment, unless otherwise provided for in the type license or permit. These guidelines enter into force on 1 January 1990

  14. Aircrew radiation exposure: sources-risks-measurement

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1994-05-01

    A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

  15. Performance of an open-source heart sound segmentation algorithm on eight independent databases.

    Science.gov (United States)

    Liu, Chengyu; Springer, David; Clifford, Gari D

    2017-08-01

    Heart sound segmentation is a prerequisite step for the automatic analysis of heart sound signals, facilitating the subsequent identification and classification of pathological events. Recently, hidden Markov model-based algorithms have received increased interest due to their robustness in processing noisy recordings. In this study we aim to evaluate the performance of the recently published logistic regression based hidden semi-Markov model (HSMM) heart sound segmentation method, by using a wider variety of independently acquired data of varying quality. Firstly, we constructed a systematic evaluation scheme based on a new collection of heart sound databases, which we assembled for the PhysioNet/CinC Challenge 2016. This collection includes a total of more than 120 000 s of heart sounds recorded from 1297 subjects (including both healthy subjects and cardiovascular patients) and comprises eight independent heart sound databases sourced from multiple independent research groups around the world. Then, the HSMM-based segmentation method was evaluated using the assembled eight databases. The common evaluation metrics of sensitivity, specificity, accuracy, as well as the [Formula: see text] measure were used. In addition, the effect of varying the tolerance window for determining a correct segmentation was evaluated. The results confirm the high accuracy of the HSMM-based algorithm on a separate test dataset comprised of 102 306 heart sounds. An average [Formula: see text] score of 98.5% for segmenting S1 and systole intervals and 97.2% for segmenting S2 and diastole intervals were observed. The [Formula: see text] score was shown to increases with an increases in the tolerance window size, as expected. The high segmentation accuracy of the HSMM-based algorithm on a large database confirmed the algorithm's effectiveness. The described evaluation framework, combined with the largest collection of open access heart sound data, provides essential resources for

  16. The Encoding of Sound Source Elevation in the Human Auditory Cortex.

    Science.gov (United States)

    Trapeau, Régis; Schönwiesner, Marc

    2018-03-28

    tuning functions in low-level auditory cortex underlie the perceived elevation of a sound source. Copyright © 2018 the authors 0270-6474/18/383252-13$15.00/0.

  17. Improvements on the directional characteristics of a calibration sound source using the Boundary Element Method

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Barrera Figueroa, Salvador; Juhl, Peter Møller

    2008-01-01

    The project Euromet-792 aims to investigate and improve methods for secondary free-field calibration of microphones. In this framework, the comparison method is being studied at DFM in relation to the more usual substitution method of microphone calibration. The design of the sound source is of p...

  18. Evolution of Sound Source Localization Circuits in the Nonmammalian Vertebrate Brainstem

    DEFF Research Database (Denmark)

    Walton, Peggy L; Christensen-Dalsgaard, Jakob; Carr, Catherine E

    2017-01-01

    The earliest vertebrate ears likely subserved a gravistatic function for orientation in the aquatic environment. However, in addition to detecting acceleration created by the animal's own movements, the otolithic end organs that detect linear acceleration would have responded to particle movement...... to increased sensitivity to a broader frequency range and to modification of the preexisting circuitry for sound source localization....

  19. Aerofoil broadband and tonal noise modelling using stochastic sound sources and incorporated large scale fluctuations

    Science.gov (United States)

    Proskurov, S.; Darbyshire, O. R.; Karabasov, S. A.

    2017-12-01

    The present work discusses modifications to the stochastic Fast Random Particle Mesh (FRPM) method featuring both tonal and broadband noise sources. The technique relies on the combination of incorporated vortex-shedding resolved flow available from Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation with the fine-scale turbulence FRPM solution generated via the stochastic velocity fluctuations in the context of vortex sound theory. In contrast to the existing literature, our method encompasses a unified treatment for broadband and tonal acoustic noise sources at the source level, thus, accounting for linear source interference as well as possible non-linear source interaction effects. When sound sources are determined, for the sound propagation, Acoustic Perturbation Equations (APE-4) are solved in the time-domain. Results of the method's application for two aerofoil benchmark cases, with both sharp and blunt trailing edges are presented. In each case, the importance of individual linear and non-linear noise sources was investigated. Several new key features related to the unsteady implementation of the method were tested and brought into the equation. Encouraging results have been obtained for benchmark test cases using the new technique which is believed to be potentially applicable to other airframe noise problems where both tonal and broadband parts are important.

  20. Compact high-power terahertz radiation source

    Directory of Open Access Journals (Sweden)

    G. A. Krafft

    2004-06-01

    Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

  1. Source of broadband Jovian Kilometric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.; Leblanc, Y.

    1987-02-01

    Broadband Jovian Kilometric radiation was observed by Voyagers 1 and 2 to be beamed away from the zenomagnetic equatorial plane. Two theories were proposed for the equatorial shadow zone. One suggested that Io plasma torus forms an obstacle to radiation produced on auroral field lines. The other theory proposed that the source is located on the outer flanks of the torus, the beaming being inherent to the emission mechanism. Results are presented which indicate that the latter is consistent with the observations and it would appear that the emission is produced by linear mode conversion of electrostatic upper hybrid to electromagnetic waves in plasma density gradients.

  2. Source of broadband Jovian Kilometric radiation

    International Nuclear Information System (INIS)

    Jones, D.; Leblanc, Y.

    1987-01-01

    Broadband Jovian Kilometric radiation was observed by Voyagers 1 and 2 to be beamed away from the zenomagnetic equatorial plane. Two theories were proposed for the equatorial shadow zone. One suggested that Io plasma torus forms an obstacle to radiation produced on auroral field lines. The other theory proposed that the source is located on the outer flanks of the torus, the beaming being inherent to the emission mechanism. Results are presented which indicate that the latter is consistent with the observations and it would appear that the emission is produced by linear mode conversion of electrostatic upper hybrid to electromagnetic waves in plasma density gradients

  3. Community Response to Multiple Sound Sources: Integrating Acoustic and Contextual Approaches in the Analysis

    Directory of Open Access Journals (Sweden)

    Peter Lercher

    2017-06-01

    Full Text Available Sufficient data refer to the relevant prevalence of sound exposure by mixed traffic sources in many nations. Furthermore, consideration of the potential effects of combined sound exposure is required in legal procedures such as environmental health impact assessments. Nevertheless, current practice still uses single exposure response functions. It is silently assumed that those standard exposure-response curves accommodate also for mixed exposures—although some evidence from experimental and field studies casts doubt on this practice. The ALPNAP-study population (N = 1641 shows sufficient subgroups with combinations of rail-highway, highway-main road and rail-highway-main road sound exposure. In this paper we apply a few suggested approaches of the literature to investigate exposure-response curves and its major determinants in the case of exposure to multiple traffic sources. Highly/moderate annoyance and full scale mean annoyance served as outcome. The results show several limitations of the current approaches. Even facing the inherent methodological limitations (energy equivalent summation of sound, rating of overall annoyance the consideration of main contextual factors jointly occurring with the sources (such as vibration, air pollution or coping activities and judgments of the wider area soundscape increases the variance explanation from up to 8% (bivariate, up to 15% (base adjustments up to 55% (full contextual model. The added predictors vary significantly, depending on the source combination. (e.g., significant vibration effects with main road/railway, not highway. Although no significant interactions were found, the observed additive effects are of public health importance. Especially in the case of a three source exposure situation the overall annoyance is already high at lower levels and the contribution of the acoustic indicators is small compared with the non-acoustic and contextual predictors. Noise mapping needs to go down to

  4. Perceptual assessment of quality of urban soundscapes with combined noise sources and water sounds.

    Science.gov (United States)

    Jeon, Jin Yong; Lee, Pyoung Jik; You, Jin; Kang, Jian

    2010-03-01

    In this study, urban soundscapes containing combined noise sources were evaluated through field surveys and laboratory experiments. The effect of water sounds on masking urban noises was then examined in order to enhance the soundscape perception. Field surveys in 16 urban spaces were conducted through soundwalking to evaluate the annoyance of combined noise sources. Synthesis curves were derived for the relationships between noise levels and the percentage of highly annoyed (%HA) and the percentage of annoyed (%A) for the combined noise sources. Qualitative analysis was also made using semantic scales for evaluating the quality of the soundscape, and it was shown that the perception of acoustic comfort and loudness was strongly related to the annoyance. A laboratory auditory experiment was then conducted in order to quantify the total annoyance caused by road traffic noise and four types of construction noise. It was shown that the annoyance ratings were related to the types of construction noise in combination with road traffic noise and the level of the road traffic noise. Finally, water sounds were determined to be the best sounds to use for enhancing the urban soundscape. The level of the water sounds should be similar to or not less than 3 dB below the level of the urban noises.

  5. Analysis and Optimal Condition of the Rear-Sound-Aided Control Source in Active Noise Control

    Directory of Open Access Journals (Sweden)

    Karel Kreuter

    2011-01-01

    Full Text Available An active noise control scenario of simple ducts is considered. The previously suggested technique of using an single loudspeaker and its rear sound to cancel the upstream sound is further examined and compared to the bidirectional solution in order to give theoretical proof of its advantage. Firstly, a model with a new approach for taking damping effects into account is derived based on the electrical transmission line theory. By comparison with the old model, the new approach is validated, and occurring differences are discussed. Moreover, a numerical application with the consideration of damping is implemented for confirmation. The influence of the rear sound strength on the feedback-path system is investigated, and the optimal condition is determined. Finally, it is proven that the proposed source has an advantage of an extended phase lag and a time delay in the feedback-path system by both frequency-response analysis and numerical calculation of the time response.

  6. The influence of signal parameters on the sound source localization ability of a harbor porpoise (Phocoena phocoena)

    NARCIS (Netherlands)

    Kastelein, R.A.; Haan, D.de; Verboom, W.C.

    2007-01-01

    It is unclear how well harbor porpoises can locate sound sources, and thus can locate acoustic alarms on gillnets. Therefore the ability of a porpoise to determine the location of a sound source was determined. The animal was trained to indicate the active one of 16 transducers in a 16-m -diam

  7. Applications and opportunities for radiation sources

    International Nuclear Information System (INIS)

    Round, K.J.

    1984-01-01

    An important spin-off benefit from the nuclear industry has been the ability to produce a wide variety of ionizing radiation sources for industrial, medical and scientific applications. These sources include radionuclides produced by irradiation of target material in reactors and cyclotrons or recovered from spent fuels, and accelerators. The uses of radiation in both medicine and industry can be expected to evolve. Traditional uses such as cancer therapy will mature and in some cases be displaced by new technology. Major new applications, including food processing and waste treatment, are expected to maintain the demand for isotopes such as cobalt 60 and to stimulate the development of economical and reliable accelerator systems. (L.L.) (Tab., 2 figs.)

  8. Facility - Radiation Source Features and User Applications

    International Nuclear Information System (INIS)

    Gover, A.; Abramovich, A.; Eichenbaum, A.L.; Kanter, M.; Sokolowski, J.; Yahalom, A.; Shiloh, J.; Schnitzer, I.; Pinhasi, Y.

    1999-01-01

    Recent measurements of the radiation characteristics of the tandem FEL prove .that the device operates as a high quality, tunable radiation source in the mm wave regime. Tuning range of 60% around a central frequency of 100 GHz was demonstrated by varying the tandem accelerator energy from 1 to 1.5 MeV with 1-1.5 Amp. Beam current. Fourier transform limited linewidth of Δ f/f -5 was measured in single-mode lasing operation. The FEL power in pulse operation (10μsec) was 10 kWatt. Operating the FEL at high repetition rate with 0.1 to 1 mSec pulses will make it possible to obtain high average power (1 kWatt) and narrow linewidth (10 -7 ). Based ,on these exceptional properties of the FEL as a high quality spectroscopic tool and as a source of high average power radiation, the FEL consortium, supported by a body of 10 radiation user groups from various universities and research institutes, embark on a new project for development of an Israeli FEL radiation user laboratory. The laboratory is presently in a design and building stage in the academic campus in Ariel. The FEL will be moved to this laboratory after completion of X-ray protection structure in the allocated building. In the first phase of development, the radiation user laboratory will consist of three user stations: a. Spectroscopic station (low average power). Material studies are planned in the fields of H.T.S.C., submicron semiconductor devices, gases. b. Material processing station (high average power). Experiments are planned in the fields of thin film ceramic sintering (including H.T.S.C.), functionally graded materials, surface treatment of metals, interaction with biological tissues. c. Atmospheric study station. Experiments are planned in the fields of aerosol, dust and clouds mapping, remote sensing of gases, wide-band mm wave communication The FEL experimental results and the user laboratory features will be described

  9. Regulation of radiation sources in Canada

    International Nuclear Information System (INIS)

    Brown, W.R.

    1989-04-01

    This paper describes in general the Canadian program for the regulation of radiation sources, with particular emphasis on radioisotope licences. The Atomic Energy Control Board is described, as are the most significant parts of the Regulations. Licensing, which is the method chosen for control, is explained by describing the assessment of an application through the enforcement of the requirements, and the overall effectiveness of the program is measured by analyzing the incidents and overexposures that have occurred in recent years

  10. Apparatus for radiation source depth determination in a material

    International Nuclear Information System (INIS)

    Campbell, P.J.

    1979-01-01

    An apparatus is disclosed for determining the depth of a radiation source within a body of material utilizing a radiation source holder moving the radiation source within the body. A plurality of switches have contacts that are fixed in relation to the movement of the radiation source within the material. Trigger means activates a particular switch at a preselected depth of the radiation source. Means for indicating the activation of a switch would thus produce a signal as a representative of the depth of the radiation source

  11. Safety of radiation sources in Slovenia

    International Nuclear Information System (INIS)

    Belicic-Kolsek, A.; Sutej, T.

    2001-01-01

    The Republic of Slovenia, a central European country which has been independent since 1991, has about 2 million inhabitants and an area of 20,256 km 2 . The Constitutional Law on Enforcement of the Basic Constitutional Charter on the Autonomy and Independence of the Republic of Slovenia, adopted on 23 June 1991 (Off. Gaz. of the R of Slovenia No. 1/91), provided that all the laws adopted by the Socialist Federal Republic (SFR) of Yugoslavia should remain in force in the Republic of Slovenia pending the adoption of appropriate legislation by the Slovene Parliament. Under the Slovene Constitution, all international treaties ratified by Slovenia constitute an integral part of Slovenia's legislation and can be applied directly. In Slovenia, all regular types of ionizing radiation source are being used for peaceful purposes and are covered by a system for their safe use and control. All radiation sources and radioactive materials are registered and under regulatory control. Inspections are carried out periodically by the Health Inspectorate of the Republic of Slovenia (HIRS) and, in the case of nuclear installations, the Slovene Nuclear Safety Administration (SNSA). Technical checks on radiation sources are carried out periodically by technical support organizations: the Jozef Stefan Institute and the Institute for Occupational Safety (IOS). (author)

  12. Sound Radiation from a Loudspeaker Cabinet using the Boundary Element Method

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren

    had been reported, based on subjective testing. This study aims to detect the reported problem. The radiation from the cabinet is calculated using the Boundary Element Method. The analysis examines both the frequency domain and the time domain characteristics (in other words, the steady state response......, in some cases becoming clearly audible. The aim of this study is to provide a tool that can evaluate the contribution from the cabinet to the overall sound radiated by a loudspeaker. The specific case of a B&O Beolab 9 early prototype has been investigated. An influence by the cabinet of this prototype...... and the impulse response) of the loudspeaker and the cabinet. A significant influence of the cabinet has been detected, which becomes especially apparent in the time domain, during the sound decay process....

  13. Kinetic theory for radiation interacting with sound waves in ultrarelativistic pair plasmas

    International Nuclear Information System (INIS)

    Marklund, Mattias; Shukla, Padma K.; Stenflo, Lennart

    2006-01-01

    A kinetic theory for radiation interacting with sound waves in an ultrarelativistic electron-positron plasma is developed. It is shown that the effect of a spatial spectral broadening of the electromagnetic pulse is to introduce a reduction of the growth rates for the decay and modulational instabilities. Such spectral broadening could be due to a finite pulse coherence length, or through the use of random phase filters, and would stabilize the propagation of electromagnetic pulses

  14. Standard light source utilizing spontaneous radiation

    International Nuclear Information System (INIS)

    Yamamoto, O.; Takenaga, M.; Tsujimoto, Y.

    1975-01-01

    A standard light source is described utilizing spontaneous radiation made by mixing a fluorescent substance LnVO 4 :X (wherein Ln is Y or Gd, and X is Dy or Eu) with a radioactive substance containing a radioactive isotope which is less in the degree of temperature variation of the intensity of emitted light and excellent in stability. Particularly when used in a light-receiving device having photomultiplier tubes, the said light source emits light quite similar to that of a thermoluminescent substance such as CaSO 4 :X (wherein X is Im, Dy, Sm or Mn), LiF or Mg 2 SiO 4 :Tb, and is excellent as a calibration high-stability standard light source for use in the above-mentioned light-receiving device. (auth)

  15. The natural sources of ionizing radiation exposure

    International Nuclear Information System (INIS)

    Maximilien, R.

    1982-01-01

    Natural sources of ionizing radiation include external sources (cosmic rays, natural radionuclides present in the crust of the earth and in building materials) and internal sources (naturally occuring radionuclides in the human body, especially the potassium 40 and radon short lived decay products). The principal ways of human exposure to theses different components in ''normal'' areas are reviewed; some examples of the variability of exposure with respect to different regions of the world or the habits of life are given. Actual estimations of the doses delivered to the organs are presented; for the main contributors to population exposure, the conversion into effective dose equivalent has been made for allowing a better evaluation of their respective importance [fr

  16. Postgraduate educational course in radiation protection and the safety of radiation sources. Standard syllabus

    International Nuclear Information System (INIS)

    2003-01-01

    The aim of the Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources is to meet the needs of professionals at graduate level, or the equivalent, for initial training to acquire a sound basis in radiation protection and the safety of radiation sources. The course also aims to provide the necessary basic tools for those who will become trainers in radiation protection and in the safe use of radiation sources in their countries. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of international recommendations and standards on radiation protection and their implementation. The participants should have had a formal education to a level equivalent to a university degree in the physical, chemical or life sciences or engineering and should have been selected to work in the field of radiation protection and the safe use of radiation sources in their countries. The present revision of the Standard Syllabus takes into account the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), IAEA Safety Series No. 115 (1996) and recommendations of related Safety Guides, as well as experience gained from the Postgraduate Educational Course on Radiation Protection and Safety of Radiation Sources held in several regions in recent years. The general aim of the course, as mentioned, is the same. Some of the improvements in the present version are as follows: The learning objective of each part is specified. The prerequisites for each part are specified. The structure of the syllabus has been changed: the parts on Principles of Radiation Protection and on Regulatory Control were moved ahead of Dose Assessment and after Biological Effects of Radiation. The part on the interface with nuclear safety was dropped and a module on radiation protection in nuclear power plants has been included. A

  17. Postgraduate educational course in radiation protection and the safety of radiation sources. Standard syllabus

    International Nuclear Information System (INIS)

    2002-01-01

    The aim of the Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources is to meet the needs of professionals at graduate level, or the equivalent, for initial training to acquire a sound basis in radiation protection and the safety of radiation sources. The course also aims to provide the necessary basic tools for those who will become trainers in radiation protection and in the safe use of radiation sources in their countries. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of international recommendations and standards on radiation protection and their implementation. The participants should have had a formal education to a level equivalent to a university degree in the physical, chemical or life sciences or engineering and should have been selected to work in the field of radiation protection and the safe use of radiation sources in their countries. The present revision of the Standard Syllabus takes into account the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), IAEA Safety Series No. 115 (1996) and recommendations of related Safety Guides, as well as experience gained from the Postgraduate Educational Course on Radiation Protection and Safety of Radiation Sources held in several regions in recent years. The general aim of the course, as mentioned, is the same. Some of the improvements in the present version are as follows: The learning objective of each part is specified. The prerequisites for each part are specified. The structure of the syllabus has been changed: the parts on Principles of Radiation Protection and on Regulatory Control were moved ahead of Dose Assessment and after Biological Effects of Radiation. The part on the interface with nuclear safety was dropped and a module on radiation protection in nuclear power plants has been included. A

  18. The status of safety of radiation sources and security of radioactive materials in Ethiopia

    International Nuclear Information System (INIS)

    Gebeyehu Wolde, G.

    2001-01-01

    Since 1993, the National Radiation Protection Authority (NRPA) has been empowered by the 'Radiation Protection Proclamation no. 79/1993' to authorize and inspect regulated activities, issue guidelines and standards and enforce the legislation and regulations. The report describes the status of the safety of radiation sources and the security of radioactive materials in Ethiopia and the progress made towards building a sound and effective national regulatory infrastructure. Also, the report highlights the challenges and difficulties encountered and concludes by indicating the way forward towards the strategic goals. (author)

  19. Perception by Operators of Approach and Withdrawal of Moving Sound Sources

    Science.gov (United States)

    1999-01-01

    Tucker, 1988; Strybel and Neal, 1994) or between stationary and moving sound sources or auditory images (Perrott and Musikant , 1977; Strybel and Neale...conditions of stimulation (Viskov, 1975; Perrott and Musikant , 1977; Strybel et al., 1989; Sabery and Perrott, 1990; Strybel et al., 1992; Strybel and...noise and its relation to masking and loudness// JASA, 1947. V.19. P. 609-619. 24. Perrott D.R., Musicant A.D. Minimum auditory movement angle: binaural

  20. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    Science.gov (United States)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1996-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  1. Stabilization of radionuclides applied in radiation sources

    International Nuclear Information System (INIS)

    Mielcarski, M.

    1989-01-01

    An attempt of comprehensive treatment of problems connected with the production of sealed radiation sources is made. In the introductory part of this work the basic information and definitions are contained. The classification systems currently applied are discussed. Attention was paid to the main fields of application. The methods of stabilization of radionuclides used for preparing radiation sources are discussed. The results of own investigations are presented, comprising the adsorption of some radionuclides on anodic Al 2 O 3 layers, stabilization in glazes and enamels, and the preparation of radioactive ceramics. In the adsorption investigations, these problems were considered as predominant which could form the basis for technological solutions. The results obtained allowed to establish the most favourable conditions of performing the process of stabilization by the use of this technique. In the case of radioactive enamels, the effect of glass composition on the yield of ionization has been investigated. Lowering of the content of radioactive component with simultaneous preserving the useful ionization ability was considered as being important. The mechanism of the observed increase of ionization caused by some inactive glass components is discussed. As concerns radioactive ceramics, a simplified method for preparing the ceramic core of cesium-137 sources is presented. This synthesis is based on the thermal transformation of moulded zeolite pellets into radioactive pollucite. Practical usefulness of different methods for the stabilization is discussed with emphasis given to those elaborated and applied in Poland. 131 refs., 37 figs., 20 tabs. (author)

  2. 75 FR 19302 - Radiation Sources on Army Land

    Science.gov (United States)

    2010-04-14

    ... possession of ionizing radiation sources by non-Army agencies (including their civilian contractors) on an... radiation sources on Army land. The Army requires Non-Army agencies (including their civilian contractors... ionizing radiation sources on an Army Installation. For the purpose of this proposed rule, ``ionizing...

  3. On the relevance of source effects in geomagnetic pulsations for induction soundings

    Science.gov (United States)

    Neska, Anne; Tadeusz Reda, Jan; Leszek Neska, Mariusz; Petrovich Sumaruk, Yuri

    2018-03-01

    This study is an attempt to close a gap between recent research on geomagnetic pulsations and their usage as source signals in electromagnetic induction soundings (i.e., magnetotellurics, geomagnetic depth sounding, and magnetovariational sounding). The plane-wave assumption as a precondition for the proper performance of these methods is partly violated by the local nature of field line resonances which cause a considerable portion of pulsations at mid latitudes. It is demonstrated that and explained why in spite of this, the application of remote reference stations in quasi-global distances for the suppression of local correlated-noise effects in induction arrows is possible in the geomagnetic pulsation range. The important role of upstream waves and of the magnetic equatorial region for such applications is emphasized. Furthermore, the principal difference between application of reference stations for local transfer functions (which result in sounding curves and induction arrows) and for inter-station transfer functions is considered. The preconditions for the latter are much stricter than for the former. Hence a failure to estimate an inter-station transfer function to be interpreted in terms of electromagnetic induction, e.g., because of field line resonances, does not necessarily prohibit use of the station pair for a remote reference estimation of the impedance tensor.

  4. On the relevance of source effects in geomagnetic pulsations for induction soundings

    Directory of Open Access Journals (Sweden)

    A. Neska

    2018-03-01

    Full Text Available This study is an attempt to close a gap between recent research on geomagnetic pulsations and their usage as source signals in electromagnetic induction soundings (i.e., magnetotellurics, geomagnetic depth sounding, and magnetovariational sounding. The plane-wave assumption as a precondition for the proper performance of these methods is partly violated by the local nature of field line resonances which cause a considerable portion of pulsations at mid latitudes. It is demonstrated that and explained why in spite of this, the application of remote reference stations in quasi-global distances for the suppression of local correlated-noise effects in induction arrows is possible in the geomagnetic pulsation range. The important role of upstream waves and of the magnetic equatorial region for such applications is emphasized. Furthermore, the principal difference between application of reference stations for local transfer functions (which result in sounding curves and induction arrows and for inter-station transfer functions is considered. The preconditions for the latter are much stricter than for the former. Hence a failure to estimate an inter-station transfer function to be interpreted in terms of electromagnetic induction, e.g., because of field line resonances, does not necessarily prohibit use of the station pair for a remote reference estimation of the impedance tensor.

  5. Capillary discharge sources of hard UV radiation

    International Nuclear Information System (INIS)

    Cachoncinlle, C; Dussart, R; Robert, E; Goetze, S; Pons, J; Mohanty, S R; Viladrosa, R; Fleurier, C; Pouvesle, J M

    2002-01-01

    We developed and studied three different extreme ultraviolet (EUV) capillary discharge sources either dedicated to the generation of coherent or incoherent EUV radiation. The CAPELLA source has been developed especially as an EUV source for the metrology at 13.4 nm. With one of these sources, we were able to produce gain on the Balmer-Hα (18.22 nm) and Hβ (13.46 nm) spectral lines in carbon plasma. By injecting 70 GW cm -3 we measured gain-length products up to 1.62 and 3.02 for the Hα and Hβ, respectively optimization of the EUV capillary source CAPELLA led to the development of an EUV lamp which emits 2 mJ in the bandwidth of the MoSi mirror, per joule stored, per shot and in full solid angle. The wall-plug efficiency is 0.2%. Stability of this lamp is better than 4% and the lamp can operate at repetition rate of 50 Hz

  6. Ionizing radiation source detection by personal TLD

    International Nuclear Information System (INIS)

    Marinkovic, O.; Mirkov, Z.

    2002-01-01

    The Laboratory for personal dosimetry has about 3000 workers under control. The most of them work in medicine. Some institutions, as big health centers, have different ionizing radiation sources. It is usefull to analyze what has been the source of irradiation, special when appears a dosimeter with high dose. Personal dosimetry equipment is Harshaw TLD Reader Model 6600 and dosimeters consist of two chips LiF TLD-100 assembled in bar-coded cards which are wearing in holders with one tissue-equivalent filter (to determine H(10)) and skin-equivalent the other (to determine H(0.07)). The calibration dosimeters have been irradiated in holders by different sources: x-ray (for 80keV and 100keV), 6 0C o, 9 0S r (for different distances from beta source) and foton beem (at radiotherapy accelerator by 6MeV, 10MeV and 18MeV). The dose ratio for two LiF cristals was calculated and represented with graphs. So, it is possible to calculate the ratio H(10)/H(0.07) for a personal TLD and analyze what has been the source of irradiation. Also, there is the calibration for determination the time of irradiation, according to glow curve deconvolution

  7. A quality control program for radiation sources

    International Nuclear Information System (INIS)

    Almeida, C.E. de; Sibata, C.H.; Cecatti, E.R.; Kawakami, N.S.; Alexandre, A.C.; Chiavegatti Junior, M.

    1982-01-01

    An extensive quality control program was established covering the following areas: physical parameters of the therapeutical machines, dosimetric standards, preventive maintenance of radiation sources and measuring instruments. A critical evaluation of this program was done after two years (1977-1979) of routine application and the results will be presented. The fluctuation on physical parameters strongly supports the efforts and cost of a quality control program. This program has certainly improved the accuracy required on the delivery of the prescribed dose for radiotherapy treatment. (Author) [pt

  8. The TAC Radiation Source for Bremsstrahlung Application

    International Nuclear Information System (INIS)

    Demir, N.

    2008-01-01

    The TAC is a project for the first Turkish radiation source and currently design study is produced with funding from the DPT (State Planning Unity). Two main part of the project will be IR-FEL and Bremsstrahlung facility. Each LINAC will provide max. electron energy of 20 MeV. The Bremsstrahlung facility at TAC will consist two of the LINAC module and will be obtained 35 MeV photon energy. This would provide a chance to investigate nuclear structure at this energy range and also some application of photonuclear physics. In this work the main parameter and plans for those of facility will be detailed

  9. Applications of Indus-1 synchrotron radiation source

    International Nuclear Information System (INIS)

    Nandedkar, R.V.

    2003-01-01

    Indus-1 is a 450 MeV electron storage ring. This is a soft X-ray and Vacuum Ultra Violet radiation source with the critical wavelength being 61 A. In this source, the first beam was stored in mid-1999 and was then made available, after initial storage and beam cleaning of the vacuum components, for beamline installation in the early 2000. Two beamlines are commissioned and are working. Other beamlines are in the advanced stage of commissioning. For Indus-1, the injection system consists of a 20 MeV classical microtron as a preinjector and a booster synchrotron that can go up to 700 MeV. For Indus-1, the injection into the storage ring is at full 450 MeV from this booster synchrotron

  10. Numerical design and testing of a sound source for secondary calibration of microphones using the Boundary Element Method

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Juhl, Peter Møller; Barrera Figueroa, Salvador

    2009-01-01

    Secondary calibration of microphones in free field is performed by placing the microphone under calibration in an anechoic chamber with a sound source, and exposing it to a controlled sound field. A calibrated microphone is also measured as a reference. While the two measurements are usually made...... apart to avoid acoustic interaction. As a part of the project Euromet-792, aiming to investigate and improve methods for secondary free-field calibration of microphones, a sound source suitable for simultaneous secondary free-field calibration has been designed using the Boundary Element Method...... of the Danish Fundamental Metrology Institute (DFM). The design and verification of the source are presented in this communication....

  11. Regulatory Control of Radiation Sources. Safety Guide

    International Nuclear Information System (INIS)

    2009-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  12. Plasma focus - a pulsed radiation source

    International Nuclear Information System (INIS)

    Blagoev, Alexandar; Zapryanov, Stanislav; Gol'tsev, Vasilii; Gemishev, Orlin

    2014-01-01

    The article is devoted to the applications of plasma focus (PF) in radiobiology. Briefly describes the principle of operation of the device and the parameters of the PF type 'Mader' at the Physics Department of the University. Phase pinch discharge zones appear hot and dense plasma, which is a source of X-ray and neutron pulse when the working gas is deuterium. These radiations are essential for biological applications. Besides these bundles are obtained from accelerated charged particles and shock wave of ionized gas. Described are some of the contributions of other authors using PF in radiobiology. Given the results in the exposure of living organisms with soft X-ray emission of PF. We examined the viability of the cells of the two types of yeasts, after irradiation with X-rays at a dose of 65 mSv, where no change was found on the performance. It is shown that soft X-ray radiation doses on the order of tens of mSv, cause a significant change in the productivity of the electronic transport in the photosynthetic apparatus of Chlamydomonas reinhardtii. Trichoderma reesei M7 shows remarkable vitality irradiation with substantial doses of hard X-ray radiation (tens Sv). Appear endoglyukonazata changes in the protein component and the residual mass

  13. Radiation sources safety and radioactive materials security regulation in Ukraine

    International Nuclear Information System (INIS)

    Smyshliaiev, A.; Holubiev, V.; Makarovska, O.

    2001-01-01

    Radiation sources are widely used in Ukraine. There are about 2500 users in industry, science, education and about 2800 in medicine. About 80,000 sealed radiation sources with total kerma-equivalent of 450 Gy*M 2 /sec are used in Ukraine. The exact information about the radiation sources and their users will be provided in 2001 after the expected completion of the State inventory of radiation sources in Ukraine. In order to ensure radiation source safety in Ukraine, a State System for regulation of activities dealing with radiation sources has been established. The system includes the following elements: establishment of norms, rules and standards of radiation safety; authorization activity, i.e. issuance of permits (including those in the form of licences) for activities dealing with radiation sources; supervisory activity, i.e. control over observance of norms, rules and standards of radiation safety and fulfilment of conditions of licences for activities dealing with radiation sources, and also enforcement. Comprehensive nuclear legislation was developed and implemented from 1991 to 2000. Radiation source safety is regulated by three main nuclear laws in Ukraine: On the use of nuclear energy and radiation safety (passed on 8 February 1995); On Human Protection from Impact of Ionizing Radiation (passed on 14 January 1998); On permissive activity in the area of nuclear energy utilization (passed on 11 January 2000). The regulatory authorities in Ukraine are the Ministry for Ecology and Natural Resources (Nuclear Regulatory Department) and the Ministry of Health (State sanitary-epidemiology supervision). According to the legislation, activities dealing with radiation sources are forbidden without an officially issued permit in Ukraine. Permitted activities with radiation sources are envisaged: licensing of production, storage and maintenance of radiation sources; licensing of the use of radiation sources; obligatory certification of radiation sources and transport

  14. The sound power emitted by a source of low acoustic impedance

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Verholt, Lars M.

    1998-01-01

    Several authors have maintained that a source of low acoustic impedance (which includes standardised reference sources of the aerodynamic type) would radiate less than the free field power in a reverberation room. However, neither computer simulations nor experiments have confirmed this assertion....

  15. Olfaction and Hearing Based Mobile Robot Navigation for Odor/Sound Source Search

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2011-02-01

    Full Text Available Bionic technology provides a new elicitation for mobile robot navigation since it explores the way to imitate biological senses. In the present study, the challenging problem was how to fuse different biological senses and guide distributed robots to cooperate with each other for target searching. This paper integrates smell, hearing and touch to design an odor/sound tracking multi-robot system. The olfactory robot tracks the chemical odor plume step by step through information fusion from gas sensors and airflow sensors, while two hearing robots localize the sound source by time delay estimation (TDE and the geometrical position of microphone array. Furthermore, this paper presents a heading direction based mobile robot navigation algorithm, by which the robot can automatically and stably adjust its velocity and direction according to the deviation between the current heading direction measured by magnetoresistive sensor and the expected heading direction acquired through the odor/sound localization strategies. Simultaneously, one robot can communicate with the other robots via a wireless sensor network (WSN. Experimental results show that the olfactory robot can pinpoint the odor source within the distance of 2 m, while two hearing robots can quickly localize and track the olfactory robot in 2 min. The devised multi-robot system can achieve target search with a considerable success ratio and high stability.

  16. Olfaction and Hearing Based Mobile Robot Navigation for Odor/Sound Source Search

    Science.gov (United States)

    Song, Kai; Liu, Qi; Wang, Qi

    2011-01-01

    Bionic technology provides a new elicitation for mobile robot navigation since it explores the way to imitate biological senses. In the present study, the challenging problem was how to fuse different biological senses and guide distributed robots to cooperate with each other for target searching. This paper integrates smell, hearing and touch to design an odor/sound tracking multi-robot system. The olfactory robot tracks the chemical odor plume step by step through information fusion from gas sensors and airflow sensors, while two hearing robots localize the sound source by time delay estimation (TDE) and the geometrical position of microphone array. Furthermore, this paper presents a heading direction based mobile robot navigation algorithm, by which the robot can automatically and stably adjust its velocity and direction according to the deviation between the current heading direction measured by magnetoresistive sensor and the expected heading direction acquired through the odor/sound localization strategies. Simultaneously, one robot can communicate with the other robots via a wireless sensor network (WSN). Experimental results show that the olfactory robot can pinpoint the odor source within the distance of 2 m, while two hearing robots can quickly localize and track the olfactory robot in 2 min. The devised multi-robot system can achieve target search with a considerable success ratio and high stability. PMID:22319401

  17. Source region of aurora kilometric radiation

    International Nuclear Information System (INIS)

    Morioka, Akira; Oya, Hiroshi; Tokumaru, Munetoshi

    1981-01-01

    This paper discusses the source region of aurora kilometric radiation (AKR), and the relation between the particle acceleration region and the polar ionosphere. The observation was made by the satellite 'Jikiken'. The AKR can be transferred to Jikiken without any interception, when the magnetic latitude of the apogee of the satellite is low. The spectra taken in June, 1980, were analyzed. The observed spectra showed the source regions of the AKR were in the aurora bands of the north and south poles. One example showed that the 200 kHz component of AKR from both poles showed the similar behavior, and another example showed that the AKR spectra from both poles showed different behavior. The altitude distribution of source regions was able to be obtained. The altitude of AKR-A was in the range between 6200 and 12000 km, and that of AKR-B was in the range of 3500 and 5200 km. The source of AKR-A was identified as that in the south hemisphere, and that of AKR-B in the north hemisphere. The asymmetric spectra of AKR-A and B showed that the spread and intensity of the electric field along magnetic lines generated above the polar ionosphere were related with the conditions of the ionosphere. (Kato, T.)

  18. Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments

    Directory of Open Access Journals (Sweden)

    Kotaro Hoshiba

    2017-11-01

    Full Text Available In search and rescue activities, unmanned aerial vehicles (UAV should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators.

  19. Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments †

    Science.gov (United States)

    Hoshiba, Kotaro; Washizaki, Kai; Wakabayashi, Mizuho; Ishiki, Takahiro; Bando, Yoshiaki; Gabriel, Daniel; Nakadai, Kazuhiro; Okuno, Hiroshi G.

    2017-01-01

    In search and rescue activities, unmanned aerial vehicles (UAV) should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS) consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators. PMID:29099790

  20. Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments.

    Science.gov (United States)

    Hoshiba, Kotaro; Washizaki, Kai; Wakabayashi, Mizuho; Ishiki, Takahiro; Kumon, Makoto; Bando, Yoshiaki; Gabriel, Daniel; Nakadai, Kazuhiro; Okuno, Hiroshi G

    2017-11-03

    In search and rescue activities, unmanned aerial vehicles (UAV) should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS) consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators.

  1. On the influence of microphone array geometry on HRTF-based Sound Source Localization

    DEFF Research Database (Denmark)

    Farmani, Mojtaba; Pedersen, Michael Syskind; Tan, Zheng-Hua

    2015-01-01

    The direction dependence of Head Related Transfer Functions (HRTFs) forms the basis for HRTF-based Sound Source Localization (SSL) algorithms. In this paper, we show how spectral similarities of the HRTFs of different directions in the horizontal plane influence performance of HRTF-based SSL...... algorithms; the more similar the HRTFs of different angles to the HRTF of the target angle, the worse the performance. However, we also show how the microphone array geometry can assist in differentiating between the HRTFs of the different angles, thereby improving performance of HRTF-based SSL algorithms....... Furthermore, to demonstrate the analysis results, we show the impact of HRTFs similarities and microphone array geometry on an exemplary HRTF-based SSL algorithm, called MLSSL. This algorithm is well-suited for this purpose as it allows to estimate the Direction-of-Arrival (DoA) of the target sound using any...

  2. Technological yields of sources for radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1990-01-01

    The present report is prepared for planners of radiation processing of any material. Sources with cobalt-60 are treated marginally, because most probably, there will be no installation of technically meaningful activity in Poland before the year 2000. Calculations are focused on accelerators of electrons, divided into two groups: versatile linacs of energy up to 13 MeV and accelerators of lower energy, below 2 MeV, of better energetical yield but of limited applications. The calculations are connected with the confrontation of the author's technological expectations during the preparation of the linac project in the late '60s, with the results of twenty years of exploitation of the machine. One has to realize that from the 150 kV input power from the mains, only 5 kV of bent and scanned beam is recovered on the conveyor. That power is only partially used for radiation induced phenomena, sometimes only a few percent, because of the demanded homogeneity of the dose, of the mode of packing of the object and its shape, of losses at the edges of the scanned area and in the spaces between boxes, and of losses during the dead time due to the tuning of the machine and dosimetric operations. The use of lower energy accelerators may be more economical in case of objects of optimum type. At the first stage, that is of the conversion of electrical power into that of the low energy electron beam, the yield is 2-3 times better than in the case of linacs. Attention has been paid to the technological aspects of electron beam conversion into the more penetrating bremsstrahlung similar to gamma radiation. The advantages of these technologies, which make it possible to control the shape of the processed object are stressed. Ten parameters necessary for a proper calculation of technological yields of radiation processing are listed. Additional conditions which must be taken into account in the comparison of the cost of radiation processing with the cost of other technologies are also

  3. Measurement of acoustic characteristics of Japanese Buddhist temples in relation to sound source location and direction.

    Science.gov (United States)

    Soeta, Yoshiharu; Shimokura, Ryota; Kim, Yong Hee; Ohsawa, Tomohiro; Ito, Ken

    2013-05-01

    Although temples are important buildings in the Buddhist community, the acoustic quality has not been examined in detail. Buddhist monks change the location and direction according to the ceremony, and associated acoustical changes have not yet been examined scientifically. To discuss the desired acoustics of temples, it is necessary to know the acoustic characteristics appropriate for each phase of a ceremony. In this study, acoustic measurements were taken at various source locations and directions in Japanese temples. A directional loudspeaker was used as the source to provide vocal acoustic fields, and impulse responses were measured and analyzed. The speech transmission index was higher and the interaural cross-correlation coefficient was lower for the sound source directed toward the side wall than that directed toward the altar. This suggests that the change in direction improves speech intelligibility, and the asymmetric property of direct sound and complex reflections from the altar and side wall increases the apparent source width. The large and coupled-like structure of the altar of a Buddhist temple may have reinforced the reverberation components and the table in the altar, which is called the "syumidan," may have decreased binaural coherence.

  4. A method for recognition of coexisting environmental sound sources based on the Fisher’s linear discriminant classifier

    DEFF Research Database (Denmark)

    Creixell Mediante, Ester; Haddad, Karim; Song, Wookeun

    2015-01-01

    A method for sound recognition of coexisting environmental noise sources by applying pattern recognition techniques is developed. The investigated technique could benefit several areas of application, such as noise impact assessment, acoustic pollution mitigation and soundscape characterization...

  5. Localization of Simultaneous Moving Sound Sources for Mobile Robot Using a Frequency-Domain Steered Beamformer Approach

    OpenAIRE

    Valin, Jean-Marc; Michaud, François; Hadjou, Brahim; Rouat, Jean

    2016-01-01

    Mobile robots in real-life settings would benefit from being able to localize sound sources. Such a capability can nicely complement vision to help localize a person or an interesting event in the environment, and also to provide enhanced processing for other capabilities such as speech recognition. In this paper we present a robust sound source localization method in three-dimensional space using an array of 8 microphones. The method is based on a frequency-domain implementation of a steered...

  6. Low frequency interference between short synchrotron radiation sources

    Directory of Open Access Journals (Sweden)

    F. Méot

    2001-06-01

    Full Text Available A recently developed analytical formalism describing low frequency far-field synchrotron radiation (SR is applied to the calculation of spectral angular radiation densities from interfering short sources (edge, short magnet. This is illustrated by analytical calculation of synchrotron radiation from various assemblies of short dipoles, including an “isolated” highest density infrared SR source.

  7. Annual individual doses for personnel dealing with ionizing radiation sources

    International Nuclear Information System (INIS)

    Poplavskij, K.K.

    1982-01-01

    Data on annual individual doses for personnel of national economy enterprises, research institutes, high schools, medical establishments dealing with ionizing radiation sources are presented. It is shown that radiation dose for the personnel constitutes only shares of standards established by sanitary legislation. Numeral values of individual doses of the personnel are determined by the type, character and scope of using ionizing radiation sources

  8. Towards a Synesthesia Laboratory: Real-time Localization and Visualization of a Sound Source for Virtual Reality Applications

    OpenAIRE

    Kose, Ahmet; Tepljakov, Aleksei; Astapov, Sergei; Draheim, Dirk; Petlenkov, Eduard; Vassiljeva, Kristina

    2018-01-01

    In this paper, we present our findings related to the problem of localization and visualization of a sound source placed in the same room as the listener. The particular effect that we aim to investigate is called synesthesia—the act of experiencing one sense modality as another, e.g., a person may vividly experience flashes of colors when listening to a series of sounds. Towards that end, we apply a series of recently developed methods for detecting sound source in a three-dimensional space ...

  9. A new radiation source: the 'CASSITRON'

    International Nuclear Information System (INIS)

    Sadat, T.; Aucouturier, J.

    1984-01-01

    The CASSITRON, a radiation source conceived and made by CGR MeV, is intended for food processing, the sterilization of disposable medical supplies, sludge sterilization, and the treatment of polymers and chemical products. Its physical characteristics are described. Also the industrial characteristics, i.e. security, simplicity, reliability, easy insertion in a production line system and multipurpose use are explained. Meeting the physical, industrial and economic needs, the CASSITRON is a secure, reliable and simple electric machine. It is a multipurpose accelerator, and can be easily inserted in a production line system. The machine is composed mainly of an electron generator, a modulator, a conversion-device to produce hard x-ray with the electron beam, and a control console. (Mori, K.)

  10. A location procedure for sound sources in reactor-technical enclosures

    International Nuclear Information System (INIS)

    Hamann, D.

    1982-07-01

    A passive method requiring one detector only has been developed for the location of sound emitting faults in nuclear power plant components. It is adapted for use in a frequency range the wavelength of which is of the same order of magnitude as characteristic dimensions of the considered enclosure. The location is performed in the following way: (1) For a fixed detector position the Auto Power Spectral Density (APSD) of the source to be located is measured. (2) For this detector position the APSD is calculated for the potential source locations. For this, the free-field APSD as well as the acoustic normal modes of the enclosure are necessary. (3) The measured APSD is compared with the theoretically obtained APSD's. (4) That APSD is determined which is most similar to the measured APSD, and consequently an information about the unknown source position is got. (author)

  11. An industrial radiation source for food processing

    International Nuclear Information System (INIS)

    Sadat, R.

    1986-01-01

    The scientific linacs realized by CGR MeV in France have been installed in several research centers, the medical accelerators of CGR MeV have been installed in radiotherapy centers all over the world, and the industrial linacs have been used for radiography in heavy industries. Based on the experience for 30 years, CGR MeV has realized a new industrial radiation source for food processing. CARIC is going to install a new machine of CGR MeV, CASSITRON, as the demand for radiation increased. This machine has been devised specially for industrial irradiation purpose. Its main features are security, simplicity and reliability, and it is easy to incorporate it into a production line. The use of CASSITRON for food industry, the ionizing effect on mechanically separated poultry meat, the capital and processing cost and others are explained. Only 10 % of medical disposable supplies is treated by ionizing energy in France. The irradiation for food decontamination, and that for industrial treatment are demanded. Therefore, CARIC is going to increase the capacity by installing a CASSITRON for sterilization. The capital and processing cost are shown. The start of operation is expected in March, 1986. At present, a CASSITRON is being installed in the SPI food processing factory, and starts operation in a few weeks. (Kako, I.)

  12. Cesium-137 as a radiation source

    International Nuclear Information System (INIS)

    McMullen, W.H.; Sloan, D.P.

    1985-01-01

    The U.S. Department of Energy (DOE) Byproducts Utilization Program (BUP) seeks to develop and encourage widespread commercial use of defense byproducts that are produced by DOE. Cesium-l37 is one such byproduct that is radioactive and decays with emission of gamma rays. The beneficial use of this radiation to disinfect sewage sludge or disinfest food commodities is actively being pursued by the program. The radiation produced by cesium-l37(Cs-l37) is identical in form to that produced by cobalt-60(Co-60), an isotope that is widely used in commercial applications such as medical product sterilization. The choice of isotope to use depends on several factors ranging from inherent properties of the isotopes to availability and cost. The BUP, although centrally concerned with the beneficial use of Cs-l37, by investigating and assessing the feasibility of various uses hopes to define appropriate circumstances where cesium or cobalt might best be used to accomplish specific objectives. This paper discusses some of the factors that should be considered when evaluating potential uses for isotopic sources

  13. Establishing control over nuclear materials and radiation sources in Georgia

    International Nuclear Information System (INIS)

    Basilia, G.

    2010-01-01

    Regulatory control over radiation sources in Georgia was lost after disintegration of the Soviet Union. A number of radiation accidents and illegal events occurred in Georgia. From 1999 Nuclear and Radiation Safety Service of the Ministry of Environmental Protection and Natural Resources is responsible for regulatory control over radiation sources in Georgia. US NRC Regulatory Assistance Program in Georgia Assist the Service in establishing long term regulatory control over sources. Main focuses of US NRC program are country-wide inventory, create National Registry of sources, safe storage of disused sources, upgrade legislation and regulation, implementation licensing and inspection activities

  14. Sound Radiation from a Supersonic Jet Passing Through a Partially Open Exhaust Duct

    Science.gov (United States)

    Kandula, Max

    2011-01-01

    The radiation of sound from a perfectly expanded Mach 2.5 cold supersonic jet of 25.4 mm exit diameter flowing through a partially open rigid-walled duct with an upstream i-deflector has been studied experimentally. In the experiments, the nozzle is mounted vertically, with the nozzle exit plane at a height of 73 jet diameters above ground level. Relative to the nozzle exit plane (NEP), the location of the duct inlet is varied at 10, 5, and -1 jet diameters. Far-field sound pressure levels were obtained at 54 jet diameters above ground with the aid of acoustic sensors equally spaced around a circular arc of radius equal to 80 jet diameters from the jet axis. Data on the jet acoustic field for the partially open duct were obtained and compared with those with a free jet and with a closed duct. The results suggest that for the partially open duct the overall sound pressure level (OASPL) decreases as the distance between the NEP and the duct inlet plane decreases, while the opposite trend is observed for the closed duct. It is also concluded that the observed peak frequency in the partially open duct increases above the free jet value as the angle from the duct axis is increased, and as the duct inlet plane becomes closer to the NEP.

  15. Methods to identify and locate spent radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs and tabs.

  16. Methods to identify and locate spent radiation sources

    International Nuclear Information System (INIS)

    1997-06-01

    The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs, tabs

  17. Methods to identify and locate spent radiation sources

    International Nuclear Information System (INIS)

    1995-07-01

    The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs and tabs

  18. The regulatory control of radiation sources in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Birol, E.

    2001-01-01

    In Turkey, the national competent authority for regulating activities involving radioactive sources is the Turkish Atomic Energy Authority, which implements the responsibility for the safety and security of radiation sources through its Radiation Health and Safety Department. The report describes the organization of the regulatory infrastructure for radiation safety in Turkey and, after a brief explanation of the current legal framework for such purpose, it refers to how the management of radiation sources is carried out and to the new provisions regarding radiation sources, including inspections of licensees and training on source safety. Finally, the report provides information on the Ikitelli radiological accident in Turkey and the current public concern about radiation sources after it happened. (author)

  19. A Survey of Sound Source Localization Methods in Wireless Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Maximo Cobos

    2017-01-01

    Full Text Available Wireless acoustic sensor networks (WASNs are formed by a distributed group of acoustic-sensing devices featuring audio playing and recording capabilities. Current mobile computing platforms offer great possibilities for the design of audio-related applications involving acoustic-sensing nodes. In this context, acoustic source localization is one of the application domains that have attracted the most attention of the research community along the last decades. In general terms, the localization of acoustic sources can be achieved by studying energy and temporal and/or directional features from the incoming sound at different microphones and using a suitable model that relates those features with the spatial location of the source (or sources of interest. This paper reviews common approaches for source localization in WASNs that are focused on different types of acoustic features, namely, the energy of the incoming signals, their time of arrival (TOA or time difference of arrival (TDOA, the direction of arrival (DOA, and the steered response power (SRP resulting from combining multiple microphone signals. Additionally, we discuss methods not only aimed at localizing acoustic sources but also designed to locate the nodes themselves in the network. Finally, we discuss current challenges and frontiers in this field.

  20. Estimates of radiation doses from various sources of exposure

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter provides an overview of radiation doses to individuals and to the collective US population from various sources of ionizing radiation. Summary tables present doses from various sources of ionizing radiation. Summary tables present doses from occupational exposures and annual per capita doses from natural background, the healing arts, nuclear weapons, nuclear energy and consumer products. Although doses from non-ionizing radiation are not as yet readily available in a concise form, the major sources of non-ionizing radiation are listed

  1. Intermittent Astrophysical Radiation Sources and Terrestrial Life

    Science.gov (United States)

    Melott, Adrian

    2013-04-01

    Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

  2. [Use of ionizing radiation sources in metallurgy: risk assessment].

    Science.gov (United States)

    Giugni, U

    2012-01-01

    Use of ionizing radiation sources in the metallurgical industry: risk assessment. Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control. The use of ionizing radiation sources requires careful risk assessment. The text lists the characteristics of the sources and the legal requirements, and contains a description of the documentation required and the methods used for risk assessment. It describes how to estimate the doses to operators and the relevant classification criteria used for the purpose of radiation protection. Training programs must be organized in close collaboration between the radiation protection expert and the occupational physician.

  3. The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl.

    Science.gov (United States)

    Baxter, Caitlin S; Nelson, Brian S; Takahashi, Terry T

    2013-02-01

    Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls (Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643-655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

  4. Three-Dimensional Elasticity Solutions for Sound Radiation of Functionally Graded Materials Plates considering State Space Method

    Directory of Open Access Journals (Sweden)

    Tieliang Yang

    2016-01-01

    Full Text Available This paper presents an analytical study for sound radiation of functionally graded materials (FGM plate based on the three-dimensional theory of elasticity. The FGM plate is a mixture of metal and ceramic, and its material properties are assumed to have smooth and continuous variation in the thickness direction according to a power-law distribution in terms of volume fractions of the constituents. Based on the three-dimensional theory of elasticity and state space method, the governing equations with variable coefficients of the FGM plate are derived. The sound radiation of the vibration plate is calculated with Rayleigh integral. Comparisons of the present results with those of solutions in the available literature are made and good agreements are achieved. Finally, some parametric studies are carried out to investigate the sound radiation properties of FGM plates.

  5. Radiological control in fires involving radiation sources

    International Nuclear Information System (INIS)

    Franco, J.O.A.; Coelho, C.P.

    1984-01-01

    The copies used during the chatter by techniques from CDTN in the I Mineiro Symposium of Fire Engineering, are presented. The chatter was based on emergency radiation control course, given by CDTN. Basic concepts, such as nuclear physics fundaments, radiation nature and detection, radiation protection and practical aspects of radiological fire emergency, were enphasized. (M.C.K.) [pt

  6. Nature and magnitude of the problem of spent radiation sources

    International Nuclear Information System (INIS)

    1991-09-01

    Various types of sealed radiation sources are widely used in industry, medicine and research. Virtually all countries have some sealed sources. The activity in the sources varies from kilobecquerels in consumer products to hundreds of pentabecquerels in facilities for food irradiation. Loss or misuse of sealed sources can give rise to accidents resulting in radiation exposure of workers and members of the general public, and can also give rise to extensive contamination of land, equipment and buildings. In extreme cases the exposure can be lethal. Problems of safety relating to spent radiation sources have been under consideration within the Agency for some years. The first objective of the project has been to prepare a comprehensive report reviewing the nature and background of the problem, also giving an overview of existing practices for the management of spent radiation sources. This report is the fulfilment of this first objective. The safe management of spent radiation sources cannot be studied in isolation from their normal use, so it has been necessary to include some details which are relevant to the use of radiation sources in general, although that area is outside the scope of this report. The report is limited to radiation sources made up of radioactive material. The Agency is implementing a comprehensive action plan for assistance to Member States, especially the developing countries, in all aspects of the safe management of spent radiation sources. The Agency is further seeking to establish regional or global solutions to the problems of long-term storage of spent radiation sources, as well as finding routes for the disposal of sources when it is not feasible to set up safe national solutions. The cost of remedial actions after an accident with radiation sources can be very high indeed: millions of dollars. If the Agency can help to prevent even one such single accident, the cost of its whole programme in this field would be more than covered. Refs

  7. Natural radiation source fabricated from commercially available instant coffee

    International Nuclear Information System (INIS)

    Kawano, Takao; Ando, Yoshiaki; Izumi, Yuuichi

    2015-01-01

    Commercially available instant coffee, Nescafe Excella, contained the radionuclide 40 K. From the instant coffee, sixteen coffee-block radiation sources were successfully fabricated with sufficiently low production dependences. The coffee-block radiation sources were examined their suitability for a radiation protection course. Although a part of radiation counts(cpm) obtained with 1 minute measurement were largely deviated, those determined by 5 minute measurements and five times of 1 minute measurement were less deviated, enabling better comprehension of the three cardinal principles of radiation protection. (author)

  8. Protection in handling ionizing radiation sources in national economy

    International Nuclear Information System (INIS)

    1986-01-01

    The collection of study texts is divided into 13 chapters giving an explanation of the structure of the atom, the properties of ionizing radiation and its interactions, quantities and units used, basic dosimetric methods, biological radiation effects, the sources of population exposure, the principles of radiation protection, technological applications of ionizing radiation, the monitoring of personnel and environment, the method of recording and filing, the method of protection from external radiation and internal contamination, health care, and requirements for protection in handling nonsealed sources. (M.D.)

  9. Detailed observations of the source of terrestrial narrowband electromagnetic radiation

    Science.gov (United States)

    Kurth, W. S.

    1982-01-01

    Detailed observations are presented of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence between the narrowband radio emissions and electron cyclotron harmonic waves near the upper hybrid resonance frequency. In addition, electromagnetic radiation propagating in the Z-mode is observed in the source region which provides an extremely accurate determination of the electron plasma frequency and, hence, density profile of the source region. The data strongly suggest that electrostatic waves and not Cerenkov radiation are the source of the banded radio emissions and define the coupling which must be described by any viable theory.

  10. Safety of radiation sources and other radioactive materials in Jordan

    International Nuclear Information System (INIS)

    Majali, M.M.

    2001-01-01

    Since joining the IAEA Model Project for upgrading radiation protection infrastructure in countries of West Asia, Jordan has amended its radiation safety legislation. The Regulatory Authority is improving its inventory system for radiation sources and other radioactive materials and also its notification, registration, licensing, inspection and enforcement systems. It has established national provisions for the management of orphan sources after they have been found. The system for the control of the radiation sources and other radioactive materials entering the country has been improved by the Regulatory Authority. (author)

  11. Sterilization plants equipped with the isotopic gamma radiation sources

    International Nuclear Information System (INIS)

    Mehta, K.; Chmielewski, A.G.

    2007-01-01

    Presentation describes different isotopic gamma radiation sources applicable for sterilization of food and medical materials. Certain gamma pallet irradiators, mini gamma irradiators and different scale gamma tote irradiators are presented. It is concluded, that about two hundreds plants with gamma radiation sources operates in different countries. However, industrially developed countries must construct much more plants than operates now

  12. Indirect detection of radiation sources through direct detection of radiolysis products

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA; Fischer, Larry E [Los Gatos, CA; Felter, Thomas E [Livermore, CA

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  13. Power Difference in Spectrum of Sound Radiation before and after Break of Phantom by Piezoelectric Extracorporeal Shock Wave Lithotriptor

    Science.gov (United States)

    Kanai, Hiroshi; Jang, Yun-Seok; Chubachi, Noriyoshi; Tanahashi, Yoshikatsu

    1994-05-01

    This paper investigates the difference in the spectrum of sound radiated before and after the break of a phantom at a focal point of the piezoelectric extracorporeal shock wave lithotriptor (ESWL) in order to identify the break time or to examine whether a calculus exists exactly at the focal point or not. From the preliminary experiments using a piece of chalk as a phantom of a calculus to measure the sound radiated when impact is applied to the chalk by an impact hammer, it is found that the bending vibration component of the vibration is exhibited in the spectrum of sound. However, for small-sized chalk shorter than 3 cm, the peak frequency of the bending vibration is higher than 20 kHz. From the experiments using a piezoeletric ESWL, it is found that there is clear difference in the power spectra among the sound radiated before the break, that radiated just after the break in the breaking process, and that radiated when the chalk does not exist at the focal point of the ESWL. These characteristics will be effective for the examination of the existence of the calculus at the focal point.

  14. Vibrational mode and sound radiation of electrostatic speakers using circular and annular diaphragms

    Science.gov (United States)

    Huang, Yu-Hsi; Chiang, Hsin-Yuan

    2016-06-01

    This study modeled two diaphragms comprising a pair of indium tin oxide (ITO) transparent plates sandwiching a vibrating diaphragm to create circular (30 mm radius) and annular (30 mm outer and 3 mm inner radius) push-pull electrostatic speakers. We then measured the displacement amplitudes and mode shapes produced by the devices. Vibration characteristics were used to predict sound pressure levels (SPLs) using the lumped parameter method (LPM) and distributed parameter method (DPM). The two measurement results obtained using a laser system were compared to the SPLs obtained using traditional acoustic measurement (AM) from 20 Hz to 20 kHz in order to verify our predictions. When using LPM and DPM, the SPL prediction results in the first three symmetric modes were in good agreement with the AM results. Under the assumption of linear operations, the DPM and amplitude-fluctuation electronic speckle pattern interferometry (ESPI) techniques proved effective in determining the visualization of mode shape (0,1)-(0,3). The use of ITO plates is a practical technique for the prediction of SPL, as well as measurement of mode shapes. The four evaluation methods, i.e. LPM, DPM, ESPI and AM, present a high degree of consistency with regard to vibrational mode and sound radiation characteristics.

  15. Modeling and control of sound radiation by simply supported and cantilever beam coupled with smart material

    Directory of Open Access Journals (Sweden)

    Vitaly Makarenko

    2007-03-01

    Full Text Available  In this paper forced vibration of the beam due to bonded piezoelectric patch is considered. When an external excitation is applied to the beam, it starts to vibrate, and the resulting acoustic response is predicted from the analytical model, which is based on Bernoulli-Euler theory of beam vibration. Analytical research of the sound radiation by a finite elastic beam is done for criteria based on minimal total sound power level. Helmholtz equation and inhomogeneous differential equation for beam transverse motion defines the solution to this problem. Such solutions were found for boundary conditions of simply supported and cantilever beams. In order to solve the task two analytical methods were used for simply supported beam. The solutions received by Fourier transform and Green functions approach give the very similar results, thus, proving methods reliability. At the case studies the exerted voltage, phase, location and piezoelectric actuator length are varied in order to establish their influence on noise attenuation.

  16. Determining radiated sound power of building structures by means of laser Doppler vibrometry

    Science.gov (United States)

    Roozen, N. B.; Labelle, L.; Rychtáriková, M.; Glorieux, C.

    2015-06-01

    This paper introduces a methodology that makes use of laser Doppler vibrometry to assess the acoustic insulation performance of a building element. The sound power radiated by the surface of the element is numerically determined from the vibrational pattern, offering an alternative for classical microphone measurements. Compared to the latter the proposed analysis is not sensitive to room acoustical effects. This allows the proposed methodology to be used at low frequencies, where the standardized microphone based approach suffers from a high uncertainty due to a low acoustic modal density. Standardized measurements as well as laser Doppler vibrometry measurements and computations have been performed on two test panels, a light-weight wall and a gypsum block wall and are compared and discussed in this paper. The proposed methodology offers an adequate solution for the assessment of the acoustic insulation of building elements at low frequencies. This is crucial in the framework of recent proposals of acoustic standards for measurement approaches and single number sound insulation performance ratings to take into account frequencies down to 50 Hz.

  17. Radiated sound and turbulent motions in a blunt trailing edge flow field

    International Nuclear Information System (INIS)

    Shannon, Daniel W.; Morris, Scott C.; Mueller, Thomas J.

    2006-01-01

    The dipole sound produced by edge scattering of pressure fluctuations at a trailing edge is most often an undesirable effect in turbomachinery and control surface flows. The ability to model the flow mechanisms associated with the production of trailing edge acoustics is important for the quiet design of such devices. The objective of the present research was to experimentally measure flow field and acoustic variables in order to develop an understanding of the mechanisms that generate trailing edge noise. The results of these experiments have provided insight into the causal relationships between the turbulent flow field, unsteady surface pressure, and radiated far field acoustics. Experimental methods used in this paper include particle image velocimetry (PIV), unsteady surface pressures, and far field acoustic pressures. The model investigated had an asymmetric 45 o beveled trailing edge. Reynolds numbers based on chord ranged from 1.2 x 10 6 to 1.9 x 10 6 . It was found that the small-scale turbulent motions in the vicinity of the trailing edge were modulated by a large scale von Karman wake instability. The broadband sound produced by these motions was also found to be dependant on the 'phase' of the wake instability

  18. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  19. Ocular exposure to ultraviolet and visible radiation from light sources

    International Nuclear Information System (INIS)

    Hietanen, M.

    1992-01-01

    Exposure of the eyes to UV radiation and blue light of artificial light sources and the sun was evaluated. A spectroradiometer was used to determine the spectral irradiance at 1 nm intervals from 250 to 800 nm. Various groups of workers are at risk of ocular over-exposure to optical radiation, outdoor workers maintenance personnel of bright light source as and wear eye-protectors with effective filtering of UV radiation and blue light. (author)

  20. Microsoft C#.NET program and electromagnetic depth sounding for large loop source

    Science.gov (United States)

    Prabhakar Rao, K.; Ashok Babu, G.

    2009-07-01

    A program, in the C# (C Sharp) language with Microsoft.NET Framework, is developed to compute the normalized vertical magnetic field of a horizontal rectangular loop source placed on the surface of an n-layered earth. The field can be calculated either inside or outside the loop. Five C# classes with member functions in each class are, designed to compute the kernel, Hankel transform integral, coefficients for cubic spline interpolation between computed values and the normalized vertical magnetic field. The program computes the vertical magnetic field in the frequency domain using the integral expressions evaluated by a combination of straightforward numerical integration and the digital filter technique. The code utilizes different object-oriented programming (OOP) features. It finally computes the amplitude and phase of the normalized vertical magnetic field. The computed results are presented for geometric and parametric soundings. The code is developed in Microsoft.NET visual studio 2003 and uses various system class libraries.

  1. Incidents with hazardous radiation sources; Zwischenfaelle mit gefaehrlichen Strahlenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Schoenhacker, Stefan [Bundesministerium fuer Inneres, Traiskirchen (Austria). Abt. 1/9 - Zivilschutzschule

    2016-07-01

    Incidents with hazardous radiation sources can occur in any country, even those without nuclear facilities. Preparedness for such incidents is supposed to fulfill globally agreed minimum standards. Incidents are categorized in incidents with licensed handling of radiation sources as for material testing, transport accidents of hazardous radiation sources, incidents with radionuclide batteries, incidents with satellites containing radioactive inventory, incidents wit not licensed handling of illegally acquired hazardous radiation sources. The emergency planning in Austria includes a differentiation according to the consequences: incidents with release of radioactive materials resulting in restricted contamination, incidents with release of radioactive materials resulting in local contamination, and incidents with the hazard of e@nhanced exposure due to the radiation source.

  2. The safety of radiation sources and radioactive materials in China

    International Nuclear Information System (INIS)

    Liu, H.

    2001-01-01

    The report describes the present infrastructure for the safety of radiation sources in China, where applications of radiation sources have become more and more widespread in the past years. In particular, it refers to the main functions of the National Nuclear Safety Administration of the State Environmental Protection Administration (SEPA), which is acting as the regulatory body for nuclear and radiation safety at nuclear installations, the Ministry of Public Health which issues licences for the use of radiation sources, and the Ministry of Public Security, which deals with the security of radiation sources. The report also refers to the main requirements of the existing regulatory system for radiation safety, i.e. the basic dose limits for radiation workers and the public, the licensing system for nuclear installations and for radioisotope-based and other irradiation devices, and the environmental impact assessment system. Information on the nationwide survey of radiation sources carried out by SEPA in 1991 is provided, and on some accidents that occurred in China due to loss of control of radiation sources and errors in the operation of irradiation facilities. (author)

  3. UV radiation sources for artificial skin tanning and protection

    International Nuclear Information System (INIS)

    Zivkovic, D.; Hrnjak, M.

    1999-01-01

    UV radiation sources for artificial tanning are more utilized at the last time. UV radiation is not harmless, so there are not safety devices for tanning. If people do not want to avoid exposure to their radiation, than it is necessary to take the prevention measure: strictly dose of UV radiation according to skin type, use of appropriate protective eye-wears and respect for inhibit of some medicaments and some cosmetic products use. (author)

  4. High frequency source localization in a shallow ocean sound channel using frequency difference matched field processing.

    Science.gov (United States)

    Worthmann, Brian M; Song, H C; Dowling, David R

    2015-12-01

    Matched field processing (MFP) is an established technique for source localization in known multipath acoustic environments. Unfortunately, in many situations, particularly those involving high frequency signals, imperfect knowledge of the actual propagation environment prevents accurate propagation modeling and source localization via MFP fails. For beamforming applications, this actual-to-model mismatch problem was mitigated through a frequency downshift, made possible by a nonlinear array-signal-processing technique called frequency difference beamforming [Abadi, Song, and Dowling (2012). J. Acoust. Soc. Am. 132, 3018-3029]. Here, this technique is extended to conventional (Bartlett) MFP using simulations and measurements from the 2011 Kauai Acoustic Communications MURI experiment (KAM11) to produce ambiguity surfaces at frequencies well below the signal bandwidth where the detrimental effects of mismatch are reduced. Both the simulation and experimental results suggest that frequency difference MFP can be more robust against environmental mismatch than conventional MFP. In particular, signals of frequency 11.2 kHz-32.8 kHz were broadcast 3 km through a 106-m-deep shallow ocean sound channel to a sparse 16-element vertical receiving array. Frequency difference MFP unambiguously localized the source in several experimental data sets with average peak-to-side-lobe ratio of 0.9 dB, average absolute-value range error of 170 m, and average absolute-value depth error of 10 m.

  5. New legislative regulations for ensuring radiation protection using ionizing radiation sources in medicine

    International Nuclear Information System (INIS)

    Boehm, K.

    2018-01-01

    European Commission Directive No. 2013/59 / EURATOM laying down basic safety requirements for the provision of radiation protection regulates the provision of radiation protection for workers with radiation sources and residents in all areas of use of ionizing radiation sources. This Directive also addresses radiation protection in the use of ionizing radiation sources in medicine. The European Commission Directive regulates the requirements for radiation protection but also extends to its scope and provisions on the use of medical radiation sources (so-called m edical exposure ) in the scope of further legislation in the field of health care, which has to be amended and modified or possibly issued new. It was necessary in the preparation of the new act on radiation protection to amend simultaneously Act no. 576/2004 on the provision of health care and services related to provision of health care and Act no. 578/2004 on Health care Providers, Health care Professionals and Organizations in Health Care and to prepare a series of implementing regulations not only to the Law on Radiation Protection but also to the Laws governing the Provision of Health Care. The paper presents changes to existing legislation on radiation protection in medical radiation and new requirements for the construction and operation of health workplaces with radiation sources, the protection of the health of patients, the requirements for instrumentation used for medical radiation and radiological instrumentation tests. (authors)

  6. Light source for synchrotron radiation x-ray topography study at Beijing Synchrotron Radiation Laboratory (BSRL)

    International Nuclear Information System (INIS)

    Zhao Jiyong; Jiang Jianhua; Tian Yulian

    1992-01-01

    Characteristics of the synchrotron radiation source for X-ray topography study at Beijing Synchrotron Radiation Laboratory (BSRL) is described, local geometrical resolution of topographies is discussed, and the diffracting intensities of white beam topography is given

  7. Separation of radiation from two sources from their known radiated sum field

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey

    2011-01-01

    This paper presents a technique for complete and exact separation of the radiated fields of two sources (at the same frequency) from the knowledge of their radiated sum field. The two sources can be arbitrary but it must be possible to enclose the sources inside their own non-intersecting minimum...

  8. State Register of Sources of Ionizing Radiation and Occupational exposure

    CERN Document Server

    2002-01-01

    One of main tasks of Radiation Protection Centre is to collect, process, systematize, store and provide the data on sources of ionizing radiation and occupational exposures. The number of sources in 2002 is provided and compared with previous year. Distribution of workers according to the type of practice is compared with previous year. Distribution of sealed sources and x-ray machines according their use is presented.

  9. Sound Source Localization through 8 MEMS Microphones Array Using a Sand-Scorpion-Inspired Spiking Neural Network.

    Science.gov (United States)

    Beck, Christoph; Garreau, Guillaume; Georgiou, Julius

    2016-01-01

    Sand-scorpions and many other arachnids perceive their environment by using their feet to sense ground waves. They are able to determine amplitudes the size of an atom and locate the acoustic stimuli with an accuracy of within 13° based on their neuronal anatomy. We present here a prototype sound source localization system, inspired from this impressive performance. The system presented utilizes custom-built hardware with eight MEMS microphones, one for each foot, to acquire the acoustic scene, and a spiking neural model to localize the sound source. The current implementation shows smaller localization error than those observed in nature.

  10. Sound Source Localization Through 8 MEMS Microphones Array Using a Sand-Scorpion-Inspired Spiking Neural Network

    Directory of Open Access Journals (Sweden)

    Christoph Beck

    2016-10-01

    Full Text Available Sand-scorpions and many other arachnids perceive their environment by using their feet to sense ground waves. They are able to determine amplitudes the size of an atom and locate the acoustic stimuli with an accuracy of within 13° based on their neuronal anatomy. We present here a prototype sound source localization system, inspired from this impressive performance. The system presented utilizes custom-built hardware with eight MEMS microphones, one for each foot, to acquire the acoustic scene, and a spiking neural model to localize the sound source. The current implementation shows smaller localization error than those observed in nature.

  11. Dosimetric analysis of radiation sources to use in dermatological lesions

    International Nuclear Information System (INIS)

    Tada, Ariane

    2010-01-01

    Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures. Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

  12. Synchrotron radiation sources: general features and vacuum system

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1985-01-01

    In the last years the electron or positron storage rings, which were until 1970 only used for high energy physics experiments, begun to be built in several countries exclusively as electromagnetic radiation source (synchrotron radiation). The sources are generally made up by injector (linear accelerator or microtron), 'booster' (synchrotron), storage ring, insertions ('Wigglers' and ondulators) and light lines. The interest by these sources are due to the high intensity, large spectrum (from infrared to the X-rays), polarization and pulsed structure of the produced radiation. For the ultra-vacuum obtainement, necessary for the functioning storage rings (p=10 -9 Torr), several special procedures are used. In Brazil the Synchrotron Radiation National Laboratory of the CNPq worked out a conceptual project of synchrotron radiation source, whose execution should begin by the construction of the several components prototypes. (L.C.) [pt

  13. Radiation sources EB and UV curing machines

    International Nuclear Information System (INIS)

    Takashi Sasaki

    1993-01-01

    This paper describes electron beam processors and related technologies for curing applications to facilitate those industrial personals who are trying to understand and evaluate the applicability and benefits of radiation curing to their products. 4 tabs., 10 figs

  14. Radiation sources EB and UV curing machines

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takashi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    This paper describes electron beam processors and related technologies for curing applications to facilitate those industrial personals who are trying to understand and evaluate the applicability and benefits of radiation curing to their products. 4 tabs., 10 figs.

  15. Natural sources of ionizing radiation in Europe

    International Nuclear Information System (INIS)

    Green, B.M.R.; Hughes, J.S.; Lomas, P.R.

    1993-01-01

    This publication maps levels of radiation of natural origin throughout the European Community (except in the Lander of the former German Democratic Republic), in Scandinavia and in Austria. The booklet explains in simple terms the basic properties and origin of different types of radiation (cosmic rays, gamma rays and radon) and their contribution to the overall exposure of the population. A glossary, a list of administrative regions used in the maps and detailed references to the data for each country are included

  16. Development of Yb-169 radiation source for new nondestructive inspection

    International Nuclear Information System (INIS)

    Yamabayashi, Hisamichi

    1994-01-01

    As the nondestructive inspection method for large structures, there has been radiography, and X-ray and γ-ray have been used as the radiation. The transmissivity of radiation through materials changes by the energy of the radiation and the density and thickness of the materials. At present about 880 γ-ray radiography apparatuses are used in Japanese private enterprises, and about 70% of them use 192 Ir γ-ray sources, and about 30% use 60 Co or 137 Cs sources. Recently the defect inspection for the worlded parts of thin wall small tubes and so on have become to be regarded as important, and the 169 Yb source that emits lower energy γ-ray is suitable to the purpose. There are many reports that 169 Yb radiography was applied successfully. As the 169 Yb radiation source, pellets and balls are on the market. 169 Yb is made by the neutron irradiation of 168 Yb in nuclear reactors. The characteristics of 169 Yb, the manufacture of 169 Yb radiation sources and the applicability of 169 Yb radiation sources to nondestructive inspection are reported. Also in Japan, many basic experiments on 169 Yb radiation sources have been carried out, and the irradiation apparatuses are small and light, and the control area can be set small. (K.I.)

  17. Challenges in Regulating Radiation Sources and Radioactive Waste in Nigeria

    International Nuclear Information System (INIS)

    Ngwakwe, C.

    2016-01-01

    Identifying challenges that hamper the efficiency and efficacy of Regulatory Infrastructure (People and Processes) as regards ensuring safety & security of radiation sources and radioactive waste is a major step towards planning for improvement. In a world constantly motivated by technological advancements, there has been considerable increase in the use of new technologies incorporating radioactive sources in both medical and industrial applications due to its perceived benefits, hence changing the dynamics of regulation. This paper brings to the fore, contemporary challenges experienced by regulators in the course of regulating radiation sources and radioactive waste in Nigeria. These challenges encountered in the business of regulating radiation sources and radioactive waste in Nigeria amongst others include; knowledge gap in the use of novel technologies for industrial applications (e.g. radiotracers in oil & gas and wastewater management), inadequate collaboration with operators to ensure transparency in their operations, inadequate cooperation from other government agencies using ionizing radiation sources, lack of synergy between relevant government agencies, difficulty in establishing standard radioactive waste management facility for orphan & disused sources, and inadequate control of NORMS encountered in industrial activities (e.g. well logging, mining). Nigerian Nuclear Regulatory Authority (NNRA), the body saddled with the responsibility of regulating the use of ionizing radiation sources in Nigeria is empowered by the Nuclear Safety and Radiation Protection Act to ensure the protection of life, property, and the environment from the harmful effects of ionizing radiation, hence are not immune to the aforementioned challenges. (author)

  18. The regulatory control of ionizing radiation sources in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, A.; Ziliukas, J.; Morkunas, G.

    1998-01-01

    The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

  19. Inspection of radiation sources and regulatory enforcement (supplement to IAEA Safety Standards Series No. GS-G-1.5)

    International Nuclear Information System (INIS)

    2010-08-01

    The achievement and maintenance of a high level of safety in the use of radiation sources depends on there being a sound legal and governmental infrastructure, including a national regulatory body with well-defined responsibilities and functions. These responsibilities and functions include establishing and implementing a system for carrying out regulatory inspections, and taking necessary enforcement actions. The Safety Requirements publication entitled Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety establishes the requirements for legal and governmental infrastructure. The term 'infrastructure' refers to the underlying structure of systems and organizations. This includes requirements concerning the establishment of a regulatory body for radiation sources and the responsibilities and functions assigned to it. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or the BSS) establish basic requirements for protection against risks associated with exposure to ionizing radiation and for the safety of radiation sources. The application of the BSS is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities to for radiation protection and safety. This TECDOC provides practical guidance on the processes for carrying out regulatory inspections and taking enforcement actions. It includes information on the development and use of procedures and standard review plans (i.e. checklists) for inspection. Specific procedures for inspection of radiation practices and sources are provided in the Appendices

  20. Inspection of radiation sources and regulatory enforcement (supplement to IAEA Safety Standards Series No. GS-G-1.5)

    International Nuclear Information System (INIS)

    2007-04-01

    The achievement and maintenance of a high level of safety in the use of radiation sources depends on there being a sound legal and governmental infrastructure, including a national regulatory body with well-defined responsibilities and functions. These responsibilities and functions include establishing and implementing a system for carrying out regulatory inspections, and taking necessary enforcement actions. The Safety Requirements publication entitled Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety establishes the requirements for legal and governmental infrastructure. The term 'infrastructure' refers to the underlying structure of systems and organizations. This includes requirements concerning the establishment of a regulatory body for radiation sources and the responsibilities and functions assigned to it. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or the BSS) establish basic requirements for protection against risks associated with exposure to ionizing radiation and for the safety of radiation sources. The application of the BSS is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities to for radiation protection and safety. This TECDOC provides practical guidance on the processes for carrying out regulatory inspections and taking enforcement actions. It includes information on the development and use of procedures and standard review plans (i.e. checklists) for inspection. Specific procedures for inspection of radiation practices and sources are provided in the Appendices

  1. Sources and levels of ambient ocean sound near the Antarctic Peninsula.

    Directory of Open Access Journals (Sweden)

    Robert P Dziak

    Full Text Available Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus and fin (B. physalus whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns, likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.

  2. Heat Transfer by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

    Science.gov (United States)

    Dreyer, Michael; Fuhrmann, Eckart

    The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The topic of this paper is to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat trans-fer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. The paper will deliver correlations for the effective contact angle and the heat transfer coefficient as a function of the relevant dimensionsless parameters as well as physical explanations for the observed behavior. The data will be used

  3. Rendering harmless and deposition of spent sealed radiation sources

    International Nuclear Information System (INIS)

    Cholerzynski, A.

    1999-01-01

    The sealed radiation sources are commonly used in medicine, agriculture, industry and scientific research. There is millions of such sources being used all over the world. The purpose of this article is to present a modes of management and disposal of spent sealed radioactive sources in different countries as well as methods being recommended in Poland

  4. Natural radiation sources fabricated from potassic chemical fertilizers and application to radiation education

    International Nuclear Information System (INIS)

    Kawano, Takao

    2010-01-01

    Potassic chemical fertilizers contain potassium, a small part of which is potassium-40. Since potassium-40 is a naturally occurring radioisotope, potassic chemical fertilizers are often used for demonstrations of the existence of natural radioisotopes and radiation. To fabricate radiation sources as educational tools, the compression and formation method developed by our previous study was applied to 13 brands of commercially available chemical fertilizers containing different amounts of potassium. The suitability (size, weight, and solidness) of thus fabricated sources was examined and 12 of them were selected as easy-to-use radiation sources at radiation educational courses. The radiation strength (radiation count rate measured by a GM survey meter) and potassium content of the 12 sources were examined. It was found that the count rate was wholly proportional to the percentage of potassium, and a new educational application was proposed and discussed for understanding that the substance emitting radiation must be the potassium present in the raw fertilizers. (author)

  5. THE ROLE OF RADIATION ACCIDENTS AND INDUSTRIAL APPLICATIONS OF IONIZING RADIATION SOURCES IN THE PROBLEM OF RADIATION DAMAGE

    OpenAIRE

    Кіхтенко, Ігор Миколайович

    2016-01-01

    Subject of research – the relevance of radiation damage at modern development of industry and medicine. In the world of radiation sources used in different fields of practice and their application in the future will increase, which greatly increases the likelihood of injury in a significant contingent of people.Research topic – the definition of the role of nuclear energy and the industrial use of ionizing radiation sources in the problem of radiation damage. The purpose of research – identif...

  6. Introduction to radiation protection practical knowledge for handling radioactive sources

    CERN Document Server

    Grupen, Claus

    2010-01-01

    The book presents an accessible account of the sources of ionising radiation and the methods of radiation protection. The basics of nuclear physics which are directly related to radiation protection are briefly discussed. The book describes the units of radiation protection, the measurement techniques, biological effects of radiation, environmental radiation, and many applications of radiation. For each chapter there is a problem section with full solutions. A detailed glossary and many useful information in appendixes complete the book. The author has addressed the issue of internationality to make sure that the text and, in particular, the complicated regulations can be easily interpreted not only in Europe and the United States but also in other countries. The subject of radiation protection requires a certain amount of mathematics. For those who have forgotten the basic rules of calculus a short refresher course in the form of a mathematical appendix is added.

  7. An investigation of the usability of sound recognition for source separation of packaging wastes in reverse vending machines.

    Science.gov (United States)

    Korucu, M Kemal; Kaplan, Özgür; Büyük, Osman; Güllü, M Kemal

    2016-10-01

    In this study, we investigate the usability of sound recognition for source separation of packaging wastes in reverse vending machines (RVMs). For this purpose, an experimental setup equipped with a sound recording mechanism was prepared. Packaging waste sounds generated by three physical impacts such as free falling, pneumatic hitting and hydraulic crushing were separately recorded using two different microphones. To classify the waste types and sizes based on sound features of the wastes, a support vector machine (SVM) and a hidden Markov model (HMM) based sound classification systems were developed. In the basic experimental setup in which only free falling impact type was considered, SVM and HMM systems provided 100% classification accuracy for both microphones. In the expanded experimental setup which includes all three impact types, material type classification accuracies were 96.5% for dynamic microphone and 97.7% for condenser microphone. When both the material type and the size of the wastes were classified, the accuracy was 88.6% for the microphones. The modeling studies indicated that hydraulic crushing impact type recordings were very noisy for an effective sound recognition application. In the detailed analysis of the recognition errors, it was observed that most of the errors occurred in the hitting impact type. According to the experimental results, it can be said that the proposed novel approach for the separation of packaging wastes could provide a high classification performance for RVMs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Regulatory control of radiation sources in Germany

    International Nuclear Information System (INIS)

    Coy, K.

    1998-01-01

    The regulatory programme governing the safe use of radioisotopes in Germany is based on the federal legislation enacted as Atomic Energy Control Act (Atomgesetz) and Radiation Protection Ordinance (Strahlen-schutzverordnung) and its implementation by the competent authorities of the individual states. Despite this highly decentralized infrastructure of enforcement the basic principles of regulations described in this paper such as authorization criteria, conditions imposed as well as depth and intensity of inspection balanced according to the individual radiation hazard involved are harmonized to the greatest possible extent by regular coordination among the competent authorities as well as a series of technical regulations such as standards and guidelines. (author)

  9. Radiation safety aspects in the use of radiation sources in industrial and heath-care applications

    International Nuclear Information System (INIS)

    Venkat Raj, V.

    2001-01-01

    The principle underlying the philosophy of radiation protection and safety is to ensure that there exists an appropriate standard of protection and safety for humans, without unduly limiting the benefits of the practices giving rise to exposure or incurring disproportionate costs in interventions. To realise these objectives, the International Commission on Radiation Protection (ICRP-60) and IAEA's Safety Series (IAEA Safety Series 120, 1996) have enunciated the following criteria for the application and use of radiation: (1) justification of practices; (2) optimisation of protection; (3) dose limitation and (4) safety of sources. Though these criteria are the basic tenets of radiation protection, the radiation hazard potentials of individual applications vary and the methods to achieve the above mentioned objectives principles are different. This paper gives a brief overview of the various applications of radiation and radioactive sources in India, their radiation hazard perspective and the radiation safety measures provided to achieve the basic radiation protection philosophy. (author)

  10. Converting the GSR part3 into a national regulations for the protection and safety of radiation sources

    International Nuclear Information System (INIS)

    Hatim, Abdulrahman

    2016-04-01

    The achievement and maintenance of a high level of Radiation Protection and Safety of Radiation Sources depends on a sound legal and governmental infrastructure, including a regulatory body with well-defined responsibilities and functions. The project aimed at converting the IAEA GRS Part 3 into National regulations in Sudan for the protection against the harmful effects of ionizing radiation and safety of radiation sources. The regulations developed covered general requirements for radiation protection, verification of safety, planned exposure situations, emergency exposure situations and existing exposure situation. The Government of Sudan is expected to empower the Sudanese Nuclear Radiological Regulatory Authority (SNRAA) and other relevant authorities to undertake the conversion of IAEA GSR Part 3 into national regulations to be used to regulate all facilities and activities in Sudan. (au)

  11. Optical Imaging of Ionizing Radiation from Clinical Sources.

    Science.gov (United States)

    Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan

    2016-11-01

    Nuclear medicine uses ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including x-rays, beam therapy, brachytherapy, and various injected radionuclides. Although PET and SPECT remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative. This article reviews optical imaging of both radionuclide- and beam-based ionizing radiation from high-energy photons and charged particles through mechanisms including radioluminescence, Cerenkov luminescence, and scintillation. Therapeutically, these visible photons have been combined with photodynamic therapeutic agents preclinically for increasing therapeutic response at depths difficult to reach with external light sources. Last, new microscopy methods that allow single-cell optical imaging of radionuclides are reviewed. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  12. Submarine groundwater discharge driven nitrogen fluxes to Long Island Sound, NY: Terrestrial vs. marine sources

    Science.gov (United States)

    Tamborski, J. J.; Cochran, J. K.; Bokuniewicz, H. J.

    2017-12-01

    Bottom-waters in Smithtown Bay (Long Island Sound, NY) are subject to hypoxic conditions every summer despite limited nutrient inputs from waste-water and riverine sources, while modeling estimates of groundwater inputs are thought to be insignificant. Terrestrial and marine fluxes of submarine groundwater discharge (SGD) were quantified to Smithtown Bay using mass balances of 222Rn, 224Ra, 226Ra and 228Ra during the spring and summer of 2014/2015, in order to track this seasonal transition period. Intertidal pore waters from a coastal bluff (terrestrial SGD) and from a barrier beach (marine SGD) displayed substantial differences in N concentrations and sources, traced using a multi-isotope approach (222Rn, Ra, δ15N-NO3-, δ18O-NO3-). NO3- in terrestrial SGD did not display any seasonality and was derived from residential septic systems and fertilizer. Marine SGD N concentrations varied month-to-month because of mixing between oxic seawater and hypoxic saline pore waters; N concentrations were greatest during the summer, when NO3- was derived from the remineralization of organic matter. Short-lived 222Rn and 224Ra SGD fluxes were used to determine remineralized N loads along tidal recirculation flow paths, while long-lived 228Ra was used to trace inputs of anthropogenic N in terrestrial SGD. 228Ra-derived terrestrial N load estimates were between 20 and 55% lower than 224Ra-derived estimates (excluding spring 2014); 228Ra may be a more appropriate tracer of terrestrial SGD N loads. Terrestrial SGD NO3- (derived from 228Ra) to Smithtown Bay varied from (1.40-12.8) ∗ 106 mol N y-1, with comparable marine SGD NO3- fluxes of (1.70-6.79) ∗ 106 mol N y-1 derived from 222Rn and 224Ra. Remineralized N loads were greater during the summer compared with spring, and these may be an important driver toward the onset of seasonal hypoxic conditions in Smithtown Bay and western Long Island Sound. Seawater recirculation through the coastal aquifer can rival the N load from

  13. Stochastic electromagnetic radiation of complex sources

    NARCIS (Netherlands)

    Naus, H.W.L.

    2007-01-01

    The emission of electromagnetic radiation by localized complex electric charge and current distributions is studied. A statistical formalism in terms of general dynamical multipole fields is developed. The appearing coefficients are treated as stochastic variables. Hereby as much as possible a

  14. Transport of cobalt-60 industrial radiation sources

    Science.gov (United States)

    Kunstadt, Peter; Gibson, Wayne

    This paper will deal with safety aspects of the handling of Cobalt-60, the most widely used industrial radio-isotope. Cobalt-60 is a man-made radioisotope of Cobalt-59, a naturally occurring non radioactive element, that is made to order for radiation therapy and a wide range of industrial processing applications including sterilization of medical disposables, food irradiation, etc.

  15. WADOSE, Radiation Source in Vitrification Waste Storage Apparatus

    International Nuclear Information System (INIS)

    Morita, Jun-ichi; Tashiro, Shingo; Kikkawa, Shizuo; Tsuboi, Takashi

    2007-01-01

    1 - Description of program or function: This is a radiation shielding program which analyzes unknown dose rates using known radiation sources. It can also evaluate radiation sources from measured dose rates. For instance, dose rates measured at several points in the hot cell of WASTEF are introduced into WADOS, and as a result, Ci of radiation sources and their positions are estimated with structural arrangement data of the WASTEF cells. The later functional addition is very useful for actual operation of a hot cell and others. NEA-1142/02: The code was originally written in non standard Fortran dialect and has been fully translated into Fortran 90, Fortran 77 compatible. 2 - Method of solution: Point kernel ray tracing method (the same method as QAD code). 3 - Restrictions on the complexity of the problem: Modeling of source form for input is available for cylinder, plate, point and others which are simplified geometrically

  16. Stability of high-brilliance synchrotron radiation sources

    International Nuclear Information System (INIS)

    Chattopadhyay, S.

    1989-12-01

    This paper discusses the following topics: characteristics of synchrotron radiation sources; stability of the orbits; orbit control; nonlinear dynamic stability; and coherent stability and control. 1 ref., 5 figs., 1 tab

  17. Rules and regulations on ionizing radiations sources installations

    International Nuclear Information System (INIS)

    1980-01-01

    The finality of this legislative text is to establish the standards and procedures for site, design, building, operation and decommissioning of nuclear installations, radioactive installations and ionizing radiations sources. This text include the commercialization of radioactive substances and equipment fabrication

  18. EVALUATION OF SIGNIFICANT ANTHROPOGENIC SOURCES OF RADIATIVELY IMPORTANT TRACE GASES

    Science.gov (United States)

    The report is an initial evaluation of significant anthropogenic sources of radiatively important trace gases. missions of greenhouse gases from human activities--including fossil fuel combustion, industrial/agricultural activities, and transportation--contribute to the increasin...

  19. Regulatory requirements of radiation and radioactive sources in India

    International Nuclear Information System (INIS)

    Sundara Rao, I.S.

    1993-01-01

    Manufacture and supply of radiation sources, their use and the disposal of radioactive materials are regulated through the application of Safe Disposal Radioactive Wastes Rules 1987. Salient aspects of these are discussed

  20. Regulatory aspects of radiation sources safety in Albania

    International Nuclear Information System (INIS)

    Dollani, K.; Kushe, R.

    1998-01-01

    In this paper are presented the regulatory aspects of the radiation sources safety in Albania, based in the new Radiological Protection Act and Regulations. The radiation protection infrastructures and procedures are described as well as their functioning for the implementation of relevant activities such as licensing and regular inspection, personal dose monitoring, emergency preparedness which are developed in the frame of the IAEA Technical Co-operation Programme. The issue of the security of radiation sources is dealt in close relation with the preparation and use of the inventory of all radiation sources in the country. A special attention is paid to the identification and location of lost sources for their finding and secure storage. (author)

  1. Guidelines on radiation protection for work with open radioactive sources

    International Nuclear Information System (INIS)

    1995-01-01

    The Danish National Institute of Radiation Protection (SIS) has published this, fourth edition of guidelines on radiation protection for work with open radiation sources. There are few changes compared to the previous edition, film doses are updated and preparation of the Danish legislation with respect to the 1991 ICRP recommendations (ICRP publication 60) is discussed. In this future recommendation the new dose limits will be proposed and new risk factors enlightened. (EG)

  2. Radiation safety aspects of the LINAC coherent light source

    International Nuclear Information System (INIS)

    Vylet, V.; Fasso, A.; Rokni, S.H.

    1998-01-01

    The radiation protection systems, which comprise the Personnel Protection System (PPS), Beam Containment System (BCS), and shielding, are described. The radiation sources and methods of their assessment are highlighted; these include bremsstrahlung and neutrons from electron beam losses, gas bremsstrahlung, synchrotron radiation, muons, and induced activity. By way of example, a plot of tissue dose as a function of distance from beam axis at the end of the experimental hutch is reproduced. (P.A.)

  3. Radiation Source Mapping with Bayesian Inverse Methods

    Science.gov (United States)

    Hykes, Joshua Michael

    We present a method to map the spectral and spatial distributions of radioactive sources using a small number of detectors. Locating and identifying radioactive materials is important for border monitoring, accounting for special nuclear material in processing facilities, and in clean-up operations. Most methods to analyze these problems make restrictive assumptions about the distribution of the source. In contrast, the source-mapping method presented here allows an arbitrary three-dimensional distribution in space and a flexible group and gamma peak distribution in energy. To apply the method, the system's geometry and materials must be known. A probabilistic Bayesian approach is used to solve the resulting inverse problem (IP) since the system of equations is ill-posed. The probabilistic approach also provides estimates of the confidence in the final source map prediction. A set of adjoint flux, discrete ordinates solutions, obtained in this work by the Denovo code, are required to efficiently compute detector responses from a candidate source distribution. These adjoint fluxes are then used to form the linear model to map the state space to the response space. The test for the method is simultaneously locating a set of 137Cs and 60Co gamma sources in an empty room. This test problem is solved using synthetic measurements generated by a Monte Carlo (MCNP) model and using experimental measurements that we collected for this purpose. With the synthetic data, the predicted source distributions identified the locations of the sources to within tens of centimeters, in a room with an approximately four-by-four meter floor plan. Most of the predicted source intensities were within a factor of ten of their true value. The chi-square value of the predicted source was within a factor of five from the expected value based on the number of measurements employed. With a favorable uniform initial guess, the predicted source map was nearly identical to the true distribution

  4. Source book of educational materials for radiation therapy. Final report

    International Nuclear Information System (INIS)

    Pijar, M.L.

    1979-08-01

    The Source Book is a listing of educational materials in radiation therapy technology. The first 17 sections correspond to the subjects identified in the ASRT Curriculum Guide for schools of radiation therapy. Each section is divided into publications and in some sections audiovisuals and training aids. Entries are listed without endorsement

  5. Control of sources of ionizing radiation in Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis [Radiation Protection Centre, Vilnius (Lithuania)

    1997-12-31

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented 2 refs., 2 tabs.; e-mail: rsc at post.omnitel.net

  6. Control of sources of ionizing radiation in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis

    1997-01-01

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented

  7. Hybrid Active/Passive Control of Sound Radiation from Panels with Constrained Layer Damping and Model Predictive Feedback Control

    Science.gov (United States)

    Cabell, Randolph H.; Gibbs, Gary P.

    2000-01-01

    There has been considerable interest over the past several years in applying feedback control methods to problems of structural acoustics. One problem of particular interest is the control of sound radiation from aircraft panels excited on one side by a turbulent boundary layer (TBL). TBL excitation appears as many uncorrelated sources acting on the panel, which makes it difficult to find a single reference signal that is coherent with the excitation. Feedback methods have no need for a reference signal, and are thus suited to this problem. Some important considerations for the structural acoustics problem include the fact that the required controller bandwidth can easily extend to several hundred Hertz, so a digital controller would have to operate at a few kilohertz. In addition, aircraft panel structures have a reasonably high modal density over this frequency range. A model based controller must therefore handle the modally dense system, or have some way to reduce the bandwidth of the problem. Further complicating the problem is the fact that the stiffness and dynamic properties of an aircraft panel can vary considerably during flight due to altitude changes resulting in significant resonant frequency shifts. These considerations make the tradeoff between robustness to changes in the system being controlled and controller performance especially important. Recent papers concerning the design and implementation of robust controllers for structural acoustic problems highlight the need to consider both performance and robustness when designing the controller. While robust control methods such as H1 can be used to balance performance and robustness, their implementation is not easy and requires assumptions about the types of uncertainties in the plant being controlled. Achieving a useful controller design may require many tradeoff studies of different types of parametric uncertainties in the system. Another approach to achieving robustness to plant changes is to

  8. Experience with qualification examinations of workers handling ionizing radiation sources

    International Nuclear Information System (INIS)

    Skokanova, K.

    1976-01-01

    The organization is described of examinations which have to be passed by supervising staff and workers using radioactive ionizing radiation sources. The requirements are listed of the examination in which these workers have to prove their professional knowledge and skills. The said examinations significantly contribute to the establishment of a system of safeguards at workplaces using ionizing radiation sources and may help economize operations at these workplaces

  9. Design and Construction of a Radiation Source of Extreme Flux

    OpenAIRE

    Valle Brozas, Francisco

    2017-01-01

    [EN]The present thesis consists of the design and construction of an X-ray source through the interaction of an ultra-intense laser with a solid and/or liquid target. Specifically, the laser technology suitable for this purpose has been investigated, the characteristics of the laser-matter interaction have been studied and possible applications of the generated X-radiation (and accelerated electrons) have been explored. Nowadays, the development of sources of ionizing radiation through la...

  10. Challenges in Regulating Radiation Sources and Associated Waste Management

    International Nuclear Information System (INIS)

    Shehzad, A.

    2016-01-01

    Radiation sources are widely used in the fields of medical, industry, agriculture, research, etc. Owing to the inherent risk of exposure to ionizing radiations while using the radiation sources and management of associated waste, safety measures are of utmost importance including robust regulatory control. Pakistan Nuclear Regulatory Authority (PNRA) is responsible for supervising all matters pertaining to nuclear safety and radiation protection in the country. Since its inception, PNRA has made rigorous efforts to regulate the radiation facilities for which regulatory framework was further strengthened by taking into account international norms/practices and implemented afterwards. However, due to vibrant use of these facilities, there are numerous challenges being faced while implementing the regulatory framework. These challenges pertains to shielding design of some facilities, control over service provider for QC/repair maintenance of radiation equipment, assessment of patient doses, and establishment of national diagnostic reference levels for radiological procedures. Further, the regulatory framework also delineate requirements to minimize the generation of associated radioactive waste as low as practicable. The requirements also necessitates that certain sealed radioactive sources (SRS) are returned to the supplier upon completion of their useful life, while other radioactive sources are required to be transported for storage at designated radioactive waste storage facilities in the country, which requires commitment from the licensee. This paper will briefly describe the challenges in regulating the radiation sources and issues related to the waste management associated with these facilities. (author)

  11. Influence of sound source location on the behavior and physiology of the precedence effect in cats.

    Science.gov (United States)

    Dent, Micheal L; Tollin, Daniel J; Yin, Tom C T

    2009-08-01

    Psychophysical experiments on the precedence effect (PE) in cats have shown that they localize pairs of auditory stimuli presented from different locations in space based on the spatial position of the stimuli and the interstimulus delay (ISD) between the stimuli in a manner similar to humans. Cats exhibit localization dominance for pairs of transient stimuli with |ISDs| from approximately 0.4 to 10 ms, summing localization for |ISDs| 10 ms, which is the approximate echo threshold. The neural correlates to the PE have been described in both anesthetized and unanesthetized animals at many levels from auditory nerve to cortex. Single-unit recordings from the inferior colliculus (IC) and auditory cortex of cats demonstrate that neurons respond to both lead and lag sounds at ISDs above behavioral echo thresholds, but the response to the lag is reduced at shorter ISDs, consistent with localization dominance. Here the influence of the relative locations of the leading and lagging sources on the PE was measured behaviorally in a psychophysical task and physiologically in the IC of awake behaving cats. At all configurations of lead-lag stimulus locations, the cats behaviorally exhibited summing localization, localization dominance, and breakdown of fusion. Recordings from the IC of awake behaving cats show neural responses paralleling behavioral measurements. Both behavioral and physiological results suggest systematically shorter echo thresholds when stimuli are further apart in space.

  12. Feed network and electromagnetic radiation source

    Science.gov (United States)

    Ardavan, Arzhang; Singleton, John; Linehan, Kevin E.; Ardavan, Houshang; Schmidt-Zwiefel, Andrea Caroline

    2017-01-17

    An antenna may include a volume polarization current radiator and a feed network. The volume polarization current radiator, includes a dielectric solid (such as a dielectric strip), and a plurality of closely-spaced excitation elements (24), each excitation element (24) being configured to induce a volume polarization current distribution in the dielectric solid proximate to the excitation element when a voltage is applied to the excitation element. The feed network is coupled to the volume polarization current radiator. The feed network also includes a plurality of passive power divider elements (32) and a plurality of passive delay elements (d1-d6) coupling the first port (30) and the plurality of second ports (108, 109, 164), the plurality of power divider elements (32) and the plurality of phase delay elements (d1-d6) being configured such that a radio-frequency signal that is applied to the first port (30) experiences a progressive change of phase as it is coupled to the plurality of second ports (108, 109, 164) so as to cause the volume polarization current distribution to propagate along the dielectric solid.

  13. Surface Deformation by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

    Science.gov (United States)

    Fuhrmann, Eckart; Dreyer, Michael E.

    The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The scientific aims are to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat transfer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. Correlations for the effective contact angle and the heat transfer coefficient shall be delivered as a function of the relevant dimensionsless parameters. The data will be used for benchmarking of commercial CFD codes and the tank design

  14. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    Ritchie, A.L.; Oldfather, D.E.; Lindner, A.F.

    1993-08-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 Gev synchrotron light source facility consisting of a 120 kev electron gun, 50 Mev linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. Figure 1. ALS floor plan. Pairs of neutron and gamma radiation monitors are shown as dots numbered from 1 to 12. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

  15. Evaluation of methods to leak test sealed radiation sources

    International Nuclear Information System (INIS)

    Arbeau, N.D.; Scott, C.K.

    1987-04-01

    The methods for the leak testing of sealed radiation sources were reviewed. One hundred and thirty-one equipment vendors were surveyed to identify commercially available leak test instruments. The equipment is summarized in tabular form by radiation type and detector type for easy reference. The radiation characteristics of the licensed sources were reviewed and summarized in a format that can be used to select the most suitable detection method. A test kit is proposed for use by inspectors when verifying a licensee's test procedures. The general elements of leak test procedures are discussed

  16. The Radiation, Interplanetary Shocks, and Coronal Sources (RISCS) Toolset

    Science.gov (United States)

    Zank, G. P.; Spann, James F.

    2014-01-01

    The goal of this project is to serve the needs of space system designers and operators by developing an interplanetary radiation environment model within 10 AU:Radiation, Interplanetary Shocks, and Coronal Sources (RISCS) toolset: (1) The RISCS toolset will provide specific reference environments for space system designers and nowcasting and forecasting capabilities for space system operators; (2) We envision the RISCS toolset providing the spatial and temporal radiation environment external to the Earth's (and other planets') magnetosphere, as well as possessing the modularity to integrate separate applications (apps) that can map to specific magnetosphere locations and/or perform the subsequent radiation transport and dosimetry for a specific target.

  17. Technological yields of sources for radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1993-01-01

    The present report is prepared for planners of radiation processing of any material. Calculations are focused on accelerators of electrons, divided into two groups: versatile linacs of energy up to 13 MeV, and accelerators of lower energy, below 2 MeV, of better energy yield but of limited applications. The calculations are connected with the confrontation of the author's technological expectations during the preparation of the linac project in the late '60s, with the results of 25 years of exploitation of the machine. One has to realize that from the 200 kW input power from the mains, only 5 kW of bent and scanned beam is recovered on the conveyor. That power is only partially used for radiation induced phenomena, because of the demanded homogeneity of the dose, of the mode of packing of the object and its shape, of edges of the scanned area and in the spaces between boxes, and of loses during the idle time due to the tuning of the machine and dosimetric operations. The use of lower energy accelerators may be more economical than that of linacs in case of objects of specific type. At the first stage already, that is of the conversion of electrical power into that of low energy electron beam, the yield is 2-3 times better than in the case of linacs. Attention has been paid to the technological aspects of electron beam conversion into the more penetrating Bremsstrahlung similar to gamma radiation. The advantages of technologies, which make possible a control of the shape of the processed object are stressed. Special attention is focused to the relation between the yield of processing and the ratio between the maximum to the minimum dose in the object under the irradiation. (author). 14 refs, 14 figs

  18. Background radiation and man-made and sources of radiation

    International Nuclear Information System (INIS)

    Babalola, I.A.

    1997-01-01

    This paper describes the development of the use of the atom and its present applications in food and agriculture, industry medicine and health care, energy-environment and research. These applications have inevitably led to concerns about nuclear safety and radioactive waste management and the need for the adoption of procedures for control, safe use and disposal of radioactive sources

  19. The regulatory infrastructure for radiation protection, the safety of radiation sources and security of radioactive materials in Ethiopia

    International Nuclear Information System (INIS)

    Gebeyehu Wolde, G.

    2003-01-01

    The application of Nuclear Techniques in Ethiopia started in the early sixties in the medical field and through time has gradually expanded to other areas. Following this growth the practice of Radiation Protection in Ethiopia dates back over 15 years. Radiation Protection Legislation 79/1993 was promulgated in December 1993, which has established an Autonomous Regulatory Authority to control and supervise the introduction and conduct of any practice involving ionizing radiation. Since 1998 the National Radiation Protection Authority has made a remarkable progress in terms of building a National Radiation Protection Infrastructure and is in a full swing transformation process towards a dynamic credible and competent regulatory Authority. The regulatory activities are designed in line with the main regulatory instruments, Notification, Authorization, Inspection and Enforcement. NRPA has a national inventory system and fully implemented the Regulatory Authority Information System (RAIS), which provides a systemic integration and will be instrumental to enhance the effectiveness of the regulatory system. A substantial progress has been made in the development and provision of support and technical services in the areas of Metrology and Calibration Services, Instrument Maintenance Service, Individual Monitoring of Personnel, Environmental and Food Monitoring and Interim Storage Facility for spent sources. Development of a national system for emergency preparedness and response is the current top agenda of NRPA. Towards ensuring an effective radiation protection and regulatory programme, NRPA is also making a proactive involvement in, expanding its outreach, information dissemination, awareness promotion and development of key human resources. In the last four years Ethiopia has been actively co-operating with IAEA in the framework of the Regional Model Projects RAF/9/024, RAF/9/028 and RAF/9/029. The inputs received through the project framework coupled with the

  20. Open Source Radiation Hardened by Design Technology

    Science.gov (United States)

    Shuler, Robert

    2016-01-01

    The proposed technology allows use of the latest microcircuit technology with lowest power and fastest speed, with minimal delay and engineering costs, through new Radiation Hardened by Design (RHBD) techniques that do not require extensive process characterization, technique evaluation and re-design at each Moore's Law generation. The separation of critical node groups is explicitly parameterized so it can be increased as microcircuit technologies shrink. The technology will be open access to radiation tolerant circuit vendors. INNOVATION: This technology would enhance computation intensive applications such as autonomy, robotics, advanced sensor and tracking processes, as well as low power applications such as wireless sensor networks. OUTCOME / RESULTS: 1) Simulation analysis indicates feasibility. 2)Compact voting latch 65 nanometer test chip designed and submitted for fabrication -7/2016. INFUSION FOR SPACE / EARTH: This technology may be used in any digital integrated circuit in which a high level of resistance to Single Event Upsets is desired, and has the greatest benefit outside low earth orbit where cosmic rays are numerous.

  1. Future radiation sources and identification of irradiated foods

    International Nuclear Information System (INIS)

    Brynjolfsson, A.

    1989-01-01

    Two major questions regarding irradiation that are raised today are: (1) Which sources should be used for irradiating food? and (2) How can irradiated foods be identified? This article considers both questions. After briefly mentioning a few of the historical stepping stones in the development of radiation sources, present and future radiation sources are discussed. Next the changes in foods caused by irradiation are considered. These changes are extremely small-so minor in fact that it is difficult to detect if the food has been irradiated. Still, these are several detection methods available, and this article describes them

  2. Radiation safety aspects of fluorescent lamp starters incorporating radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Sadagopan, Geetha [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Shukla, V.K. [Environmental Assessment Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    2000-05-01

    A fluorescent lamp starter is a switch applies the voltage to the fluorescent tube after sufficient preheating to allow the tube to conduct an electric current. Radioactive substances used in the starters are {sup 85}Kr, {sup 147}Pm, {sup 3}H and {sup 232}Th. In India, fluorescent lamp starters are classified as consumer products and users are outside regulatory control. However, regulatory control is exercised over the manufacturers at the production stage. Tritium activity measured in the lamp starters ranged from 400-4500 Bq with a mean activity of 1.78 kBq. Thorium activity measured varied from 0.44-3.3 mg. The results of radiation safety assessment of the workplace and radioactivity estimation in the starters are discussed in this paper. (author)

  3. Radiation safety aspects of fluorescent lamp starters incorporating radiation source

    International Nuclear Information System (INIS)

    Sadagopan, Geetha; Shukla, V.K.

    2000-01-01

    A fluorescent lamp starter is a switch applies the voltage to the fluorescent tube after sufficient preheating to allow the tube to conduct an electric current. Radioactive substances used in the starters are 85 Kr, 147 Pm, 3 H and 232 Th. In India, fluorescent lamp starters are classified as consumer products and users are outside regulatory control. However, regulatory control is exercised over the manufacturers at the production stage. Tritium activity measured in the lamp starters ranged from 400-4500 Bq with a mean activity of 1.78 kBq. Thorium activity measured varied from 0.44-3.3 mg. The results of radiation safety assessment of the workplace and radioactivity estimation in the starters are discussed in this paper. (author)

  4. Application of large radiation sources in chemical processing industry

    International Nuclear Information System (INIS)

    Krishnamurthy, K.

    1977-01-01

    Large radiation sources and their application in chemical processing industry are described. A reference has also been made to the present developments in this field in India. Radioactive sources, notably 60 Co, are employed in production of wood-plastic and concrete-polymer composites, vulcanised rubbers, polymers, sulfochlorinated paraffin hydrocarbons and in a number of other applications which require deep penetration and high reliability of source. Machine sources of electrons are used in production of heat shrinkable plastics, insulation materials for cables, curing of paints etc. Radiation sources have also been used for sewage hygienisation. As for the scene in India, 60 Co sources, gamma chambers and batch irradiators are manufactured. A list of the on-going R and D projects and organisations engaged in research in this field is given. (M.G.B.)

  5. Ionizing radiation sources used in medical applications in Brazil

    International Nuclear Information System (INIS)

    Araujo, A.M.C.; Carlos, M.T.; Cruz, L.R.F.; Domingues, C.; Farias, J.T.; Ferreira, R.; Figueiredo, L.; Peixoto, J.E.; Oliveira, S.M.V.; Drexler, G.

    1991-02-01

    Preliminary data about ionizing radiation sources used in medical applications and obtained through a national programme by IRD/CNEN together with Brazilian health authorities are presented. The data presentation follows, as close as possible, recommendations given by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR). This programme has two main aims: First: to contribute for research in the field of ionizing radiation effects and risks including information about equipment quality control and procedures adopted by professionals working in Radiation Medicine. Second: to investigate the radiation protection status in Brazil, in order to give assistance to Brazilian health authorities for planning regional radiation programmes and training programmes for medical staffs. (F.E.). 13 refs, 19 figs, 34 tabs

  6. Solar radiation data sources, applications, and network design

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    A prerequisite to considering solar energy projects is to determine the requirements for information about solar radiation to apply to possible projects. This report offers techniques to help the reader specify requirements in terms of solar radiation data and information currently available, describes the past and present programs to record and present information to be used for most requirements, presents courses of action to help the user meet his needs for information, lists sources of solar radiation data and presents the problems, costs, benefits and responsibilities of programs to acquire additional solar radiation data. Extensive background information is provided about solar radiation data and its use. Specialized information about recording, collecting, processing, storing and disseminating solar radiation data is given. Several Appendices are included which provide reference material for special situations.

  7. Radiometric analyzer with plural radiation sources and detectors

    International Nuclear Information System (INIS)

    Arima, S.; Oda, M.; Miyashita, K.; Takada, M.

    1977-01-01

    A radiometric analyzer for measuring characteristics of a material by radiation comprises a plurality of systems in which each consists of a radiation source and a radiation detector which are the same in number as the number of elements of the molecule of the material and a linear calibration circuit having inverse response characteristics (calibration curve) of the respective systems of detectors, whereby the measurement is carried out by four fundamental rules by operation of the mutual outputs of said detector system obtained through said linear calibration circuit. One typical embodiment is a radiometric analyzer for hydrocarbons which measures the density of heavy oil, the sulfur content and the calorific value by three detector systems which include a γ-ray source (E/sub γ/ greater than 50 keV), a soft x-ray source (Ex approximately 20 keV), and a neutron ray source. 2 claims, 6 figures

  8. Control of radiation sources in Brazil

    International Nuclear Information System (INIS)

    Oliveira, Silvia Maria Velasques de; Menezes, Sergio Ferreira; Alves Filho, Aristeu Dacio; Xavier, Ana Maria

    1997-01-01

    The radiological accident occurred in Goiania, in 1987, brought to light several deficiencies in the conduction of the licensing processes of medical, industrial and research facilities that handle radioisotopes as well as int he control of radioactive sources in Brazil. The objective of this article is to describe some of the technical and administrative measures taken to ensure the adoption of appropriate radiological safety standards throughout the country, thus reducing the incidence of radiological accidents. (author)

  9. A "looming bias" in spatial hearing? Effects of acoustic intensity and spectrum on categorical sound source localization.

    Science.gov (United States)

    McCarthy, Lisa; Olsen, Kirk N

    2017-01-01

    Continuous increases of acoustic intensity (up-ramps) can indicate a looming (approaching) sound source in the environment, whereas continuous decreases of intensity (down-ramps) can indicate a receding sound source. From psychoacoustic experiments, an "adaptive perceptual bias" for up-ramp looming tonal stimuli has been proposed (Neuhoff, 1998). This theory postulates that (1) up-ramps are perceptually salient because of their association with looming and potentially threatening stimuli in the environment; (2) tonal stimuli are perceptually salient because of an association with single and potentially threatening biological sound sources in the environment, relative to white noise, which is more likely to arise from dispersed signals and nonthreatening/nonbiological sources (wind/ocean). In the present study, we extrapolated the "adaptive perceptual bias" theory and investigated its assumptions by measuring sound source localization in response to acoustic stimuli presented in azimuth to imply looming, stationary, and receding motion in depth. Participants (N = 26) heard three directions of intensity change (up-ramps, down-ramps, and steady state, associated with looming, receding, and stationary motion, respectively) and three levels of acoustic spectrum (a 1-kHz pure tone, the tonal vowel /ә/, and white noise) in a within-subjects design. We first hypothesized that if up-ramps are "perceptually salient" and capable of eliciting adaptive responses, then they would be localized faster and more accurately than down-ramps. This hypothesis was supported. However, the results did not support the second hypothesis. Rather, the white-noise and vowel conditions were localized faster and more accurately than the pure-tone conditions. These results are discussed in the context of auditory and visual theories of motion perception, auditory attentional capture, and the spectral causes of spatial ambiguity.

  10. Metals, organic compounds, and nutrients in Long Island Sound: sources, magnitudes, trends, and impacts

    Science.gov (United States)

    Mullaney, John R.; Varekamp, J.C.; MCElroy, A.E.; Brsslin, V.T.

    2014-01-01

    Long Island Sound (LIS) is a relatively shallow estuary with a mean depth of 20 m (maximum depth 49 m) and a unique hydrology and history of pollutant loading. Those factors have contributed to a wide variety of contamination problems in its muddy sediments, aquatic life and water column. The LIS sediments are contaminated with a host of legacy and more recently released toxic compounds and elements related to past and present wastewater discharges and runoff. These include non-point and storm water runoff and groundwater discharges, whose character has changed over the years along with the evolution of its watershed and industrial history. Major impacts have resulted from the copious amounts of nutrients discharged into LIS through atmospheric deposition (N), domestic and industrial waste water flows, fertilizer releases, and urban runoff. All these sources and their effects are in essence the result of human presence and activities in the watershed, and the severity of pollutant loading and their impacts generally scales with total population in the watersheds surrounding LIS. Environmental legislation passed since the mid-to late 1900s (e.g., Clean Air Act, Clean Water Act) has had a beneficial effect, however, and contaminant loadings for many toxic organic and inorganic chemicals and nutrients have diminished over the last few decades (O’Shea and Brosnan 2000; Trench, et al, 2012; O’Connor and Lauenstein 2006; USEPA 2007). Major strides have been made in reducing the inflow of nutrients into LIS, but cultural eutrophication is still an ongoing problem and nutrient control efforts will need to continue. Nonetheless, LIS is still a heavily human impacted estuary (an ‘Urban Estuary’, as described for San Francisco Bay by Conomos, 1979), and severe changes in water quality and sediment toxicity as well as ecosystem shifts have been witnessed over the relatively short period since European colonization in the early 1600s (Koppelman et al., 1976).

  11. Regulatory control for safe usage of radiation sources in India

    International Nuclear Information System (INIS)

    Ghosh, P.K.; Sonawane, A.U.

    1998-01-01

    The widespread applications of radioactive materials and radiation generating equipment in the field of industry, medicine agriculture and research in India necessitated the establishment of an efficient regulatory framework and consequently the Atomic Energy Regulatory Board (AERB) was constituted to exercise regulatory control over the safe usage of the radioactive materials and the radiation generating equipment. The Atomic Energy Act, 1962 and the Radiation Protection Rules, 1971 promulgated under the Act forms the basis of radiation safety in India and Chairman, AERB is the Competent Authority to enforce the regulatory provisions of the Radiation Protection Rules, 1971, for safe use of radiation source in the country. AERB has published a number of documents such as Radiation Surveillance Procedures, Standards, Codes, Guides and Manuals for safe use and handling of radioactive materials and radiation generating equipment. Apart from nuclear fuel cycle documents, these publications pertain to industrial radiography, medical application of radiation, transport of radioactive material, industrial gamma irradiators, X-ray units etc. AERB safety related publications are based on international standards e.g. BSS, IAEA, ICRP, ISO etc. This paper outlines the methodology of regulatory control exercised by AERB for safe use of the radioactive materials and the radiation generating equipment in the country. (author)

  12. Training of human resources on radiation protection and safe use of radiation sources. Argentine experience

    International Nuclear Information System (INIS)

    Biaggio, Alfredo L.; Nasazzi, Nora B.; Arias, Cesar

    2004-01-01

    Argentina has a long experience in Radiation Protection training since 25 years ago. In the present work we analyse those variable and non variable training aspects according to scientific development, increasing radiation source diversity (including new concepts like orphan sources and security), mayor concern about patient in Radiation Protection, previous exposures, etc. We comment what we consider the main steps in the training of Radiation Protection specialists, like university degree, post graduate education distinguishing between formative and informative contents and on the job training. Moreover, we point out the trainees aptitudes and attitudes to be developed in order to work properly in this interdisciplinary field. (author)

  13. Radiation in the living environment: sources, exposure and effects

    International Nuclear Information System (INIS)

    Gupta, Rashi

    2013-01-01

    We are living in a milieu of radiations and continuously exposed to radiations from natural sources from conception to death. We are exposed to radiation from Sun and outer space, radioactive materials present in the earth, house we live in, buildings and workplace, food we eat and air we breath. Each flake of snow, grain of soil, drop of rain, a flower, and even each man in the street is a source of this radiation. Even our own bodies contain naturally occurring radioactive elements. The general belief is that the radiations are harmful and everybody is scared of the same. The cancer is the most important concern on account of exposure to Ionizing Radiation which is initiated by the damage to DNA. The level of exposure depends on the environmental and working conditions and may vary from low to moderate to high and depending on the same the exposed humans can be classified as general public, non nuclear workers (NNW) and nuclear workers (NW). Though, the LNT theory which is considered to be the radiation paradigm considers all radiation at all levels to be harmful and the -severity of the deleterious effect increases with the increase in dose, however, the available literature, data and reports (epidemiological and experimental) speaks otherwise particularly at low levels. The purpose of this paper is to address the question, whether the radiation is harmful at all levels or it is simply media hype and the truth is different, and to promote harmony with nature and to improve our quality of life with the knowledge that cancer mortality rates decrease following exposure to LLIR. Various sources of radiation exposure and the subsequent consequences will be discussed. (author)

  14. Radiation protection and regulatory aspects in the use of radiation sources

    International Nuclear Information System (INIS)

    Sen, Amit; Dash Sharma, P.K.; Sonawane, A.U.

    2012-01-01

    The uses of ionising radiation sources (i.e. radioisotopes and radiation generating equipment such as accelerators and X-ray machines) for multifarious applications in industry, medicine, agriculture, research and teaching have been significantly increasing all over the world. In India, the application of radiation sources in various fields has registered phenomenal growth during the last decade. The use of radiation sources mainly include radiation processing for food preservation and sterilization of healthcare products, radiotherapy for treatment of cancer, nuclear medicine for diagnosis and therapy, gamma chambers for several R and D studies, blood irradiators, industrial radiography for non destructive examinations of steel structures, industrial ionising radiation gauging devices for monitoring/measurement of on-line quality control parameters (e.g. thickness, level, density, moisture, elemental analysis), consumer products such as gaseous tritium light sources (GTLS), gaseous tritium light devices (GTLD), ionisation chamber smoke detectors (ICSD), fluorescent light starters, antistatic devices and incandescent gas mantles containing thorium etc. All these beneficial applications involve use of both sealed and unsealed radioactive sources and amount of radioactivity varies from few kBq (μCi) to hundreds of TBq (thousands of curies). Radiation sources emit ionising radiations and if not handled properly and safely, may give rise to potential exposures leading to an unacceptable hazard. Therefore, it is necessary to ensure a high standard of safety and reliability in handling of radiation equipment and sources through their careful design by ensuring adequate built-in-safety as per applicable national/international standard, safe operation and periodic maintenance procedures, safe transport from one place to another, secured storage when not in use, physical security to radiation sources, effective emergency response plans and preparedness, including safe

  15. Environmental radiation safety source term evaluation program

    International Nuclear Information System (INIS)

    Moss, O.R.; Filipy, R.E.; Cannon, W.C.; Craig, D.K.

    1977-04-01

    Plutonium-238 is currently used in the form of a pure refractory oxide as a power source on a number of space vehicles that have already been or will be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere and impact with the earth's surface without releasing any plutonium, the possibility of such an event can never be absolutely excluded. Three separate tasks were undertaken in this study. The interactions between soils and 238 PuO 2 aerosols which might be created in a space launch about environment were examined. Aging of the plutonium-soil mixture under a humid atmosphere showed a trend toward the slow coagulation of two dilute aerosols. Studies on marine animals were conducted to assess the response of 238 PuO 2 pellets to conditions found 60 feet below the ocean surface. Ultrafilterability studies measured the solubility of 238 PuO 2 as a function of time, temperature, suspension concentration and molality of solvent

  16. Molecular environmental science and synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.E. Jr. [Stanford Univ., CA (United States)

    1995-12-31

    Molecular environmental science is a relatively new field but focuses on the chemical and physical forms of toxic and/or radioactive contaminants in soils, sediments, man-made waste forms, natural waters, and the atmosphere; their possible reactions with inorganic and organic compounds, plants, and organisms in the environment; and the molecular-level factors that control their toxicity, bioavailability, and transport. The chemical speciation of a contaminant is a major factor in determining its behavior in the environment, and synchrotron-based X-ray absorption fine structure (XAFS) spectroscopy is one of the spectroscopies of choice to quantitatively determine speciation of heavy metal contaminants in situ without selective extraction or other sample treatment. The use of high-flux insertion device beam lines at synchrotron sources and multi-element array detectors has permitted XAFS studies of metals such as Se and As in natural soils at concentration levels as low as 50 ppm. The X-ray absorption near edge structure of these metals is particularly useful in determining their oxidation state. Examples of such studies will be presented, and new insertion device beam lines under development at SSRL and the Advanced Photon Source for molecular environmental science applications will be discussed.

  17. Possible sources of radiation in indoor environment

    International Nuclear Information System (INIS)

    Djukanovic, M.

    1997-01-01

    More locations and building material will be needed to solve the housing needs, actually the future quantities will equal the total of all the previous building. And presently one quarter of the world population is already homeless. The development of human civilization in the new technological era goes on extremely quickly. In the search for new spaces, in the last decade of the 20th century, in town renovation planning the application of subterranean civil engineering is very popular. Below ground level, the new towns are built with many stories, with exclusively artificial light and artificial climate. There is not the slightest possibility of natural ventilation. These spaces have not been investigated as regards the contents of radon. Man is not adapted to spend most of the time in under artificial conditions. It is still to be discovered how it will affect humans and what is the degree of exposure to ionizing radiation in such conditions. It might be better to abandon underground construction before the adverse effects are proved. Previous mistakes in building must be overcome and new technologies applied as well as sustainable development in the future. (author)

  18. Sound reduction by metamaterial-based acoustic enclosure

    Directory of Open Access Journals (Sweden)

    Shanshan Yao

    2014-12-01

    Full Text Available In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

  19. Sound reduction by metamaterial-based acoustic enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shanshan; Li, Pei; Zhou, Xiaoming; Hu, Gengkai, E-mail: hugeng@bit.edu.cn [Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education and School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 (China)

    2014-12-15

    In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

  20. Control of radioisotopes and radiation sources in Indonesia

    International Nuclear Information System (INIS)

    Ridwan, M.

    2001-01-01

    Radioisotopes and radiation sources are extensively used in Indonesia in medicine, industry, mining, agriculture and research. These materials are controlled by the regulatory authority, according to established legal procedures. The Nuclear Energy Control Board of Indonesia (BAPETEN), which was established in 1998 through the Nuclear Energy Act No. 10/1997, is entrusted with the control of any application of nuclear energy, including the application of radioisotopes and radiation sources, through regulation, licensing and inspection. The control is aimed to assure welfare, security and peace, the safety and health of workers and the public, and environmental protection. The number of licences issued to date is around 2400, consisting of 1600 licences for radioisotopes and radiation sources used in hospitals, 347 in radiography, 256 in industry, 53 in mining, and the rest in many other areas such as research and agriculture. A licence can cover one or more radioisotopes or radiation sources, depending on the location of the user institution. These radioisotopes and radiation sources are Co-60, Cs-137, Ir-192, Ra-226, Am-241, Sr-90, Kr-85, Pm-147, linear accelerator and X-ray, and short half-life radioisotopes such as I-125, I-131 and Tc-99m. There are 10 LINACs, 27 X-ray medicines, 61 radioisotope devices for Co-60 and Cs-137, and 10 mHDR Ir-192 for therapeutic purposes currently used in Indonesia and some Ra-226 in storage. Any activity related to the application of nuclear energy is required to be conducted in a manner which observes safety and security. According to the legal requirements, each user has to employ at least one radiation safety officer. To improve the control of the application of radiation sources and radioactive material in the country, BAPETEN introduced some new approaches to the users, including regular dialogues with radiation safety officers and the management of the users, requalification for radiation protection officers twice in five

  1. Evaluation of integrity of radiation sources of nuclear gauges

    International Nuclear Information System (INIS)

    Torohate, Wiclif Francisco

    2016-01-01

    Nuclear equipment meters are mainly used in the industry in quality control and process control. The principle of operation consists in a shielded radioactive source together with a radiation detector such that the radiation interacts with the material to be analyzed before reaching the detector, providing real time data. Can be as their fixed and mobile mobility, the unique properties of ionizing radiation are used in three basic modes, transmission, backscatter or dispersion or induced (reactive). With the advancement and technological modernization in the world, the demand for nuclear gauges becomes increasingly larger. Currently in Brazil there are about 465 process control plants and 21 portable systems and Mozambique about 45 facilities using nuclear gauges. This font registration is done through a process called source inventory that allows also to know the category of the source, the danger or risk to human health that the source offers. The handling of this equipment requires personnel, certified, skilled and well trained in radiation protection area in accordance with the requirements of the various CNEN Rules. Due to the presence of radioactive source and because these devices are used by workers risk because there external radiation. In this context, we made the smear test in two fixed meters from the IRD industry laboratory, which determines the integrity of the source package, mandatory item in periodic integrity testing of the radiation source of this type of device. A set of procedures is made for its implementation as an evaluation of the radiological risk by radiological survey. It was intended to contribute to the learning handling and safe use of these meters. (author)

  2. Dosimetry services for internal and external radiation sources

    International Nuclear Information System (INIS)

    1988-01-01

    The Canadian Atomic Energy Control Board (AECB) sets radiation dose limits for the operation of nuclear facilities and the possession of prescribed substances within Canada. To administer these regulations the AECB must be satisfied that the dosimetry services used by a licensee meet adequate standards. Licensees are required to use the Occupational Dosimetry Service operated by the Bureau of Radiation and Medical Devices, Department of National Health and Welfare (BRMD) to determine doses from external sources of radiation, except where a detailed rationale is given for using another service. No national dosimetry service exists for internal sources of radiation. Licensees who operate or use a dosimetry service other than the BRMD must provide the AECB with evidence of the competence of the staff and adequacy of the equipment, techniques and procedures; provide the AECB with evidence that a quality assurance program has been implemented; and send individual dose or exposure data to the National Dose Registry. (L.L.)

  3. Strengthening the security of radiation sources in Ghana

    International Nuclear Information System (INIS)

    Emi-Reynolds, G.; Banini, G.K.; Flecther, J.J.; Ennison, I.; Schandorf, C.

    1998-01-01

    Legislative instrument LI 1559 of 1993 established the Radiation Protection Board (RPB) as the National Competent Authority (NCA) on radiation matters in Ghana. The Board advises Government through the Ghana Atomic Energy Commission on matters relating to radiation safety, security of sources, sales, import and export, contamination in food and environment, among others. It has wide ranging regulatory power and works in association with country authorities. The regulations in place for controlling the movement and use of radioactive materials in Ghana are discussed. Accountability for radioactive materials especially for those which were brought in before the establishment of the RPB have been the focus of our discussion. The need to for intensify educational programs for the public on matters relating to effect of radiation on man and environment is recommended. Strengthening of regulatory control of sources and intensifying efforts against smuggling, unauthorised use and systems for notification on radioactive transport accidents are noted. (author)

  4. Radiological Protection Experience with natural sources of radiation

    International Nuclear Information System (INIS)

    Quindos, L. S.; Fernandez, P. L.; Vinuela, J.; Arteche, J.; Sainz, G.; Gomez, J.; Matarranz

    2003-01-01

    During the last twenty five years the research Radon Group of the Medical Physics Unit of the University of Cantabria has been involved in projects concerning the measurement of natural radiation, in special that coming from radon gas. At this moment we have available for this field a lot of information in different formats, as paper, video and CD, interesting not only for public in general but also for professionals interested in the evaluation of doses coming from natural sources of radiation. (Author)

  5. Protection from potential exposures: application to selected radiation sources

    International Nuclear Information System (INIS)

    1997-09-01

    This ICRP Report begins with the general principles of radiation protection in the case of potential exposures, followed by special issues in application and compliance with regulatory aims. The rest of the report uses event trees or fault trees to derive the logical structure of six scenarios of potential exposure, i.e. two irradiators, a large research accelerator, an accelerator for industrial isotope production, an industrial radiography device using a mobile source of radiation, and finally a medical gamma radiotherapy device. (UK)

  6. Radiation safety of sealed sources and equipment containing them

    International Nuclear Information System (INIS)

    1993-01-01

    The guide gives information and requirements concerning the technical construction, installation, use and licensing of devices containing sealed radioactive sources in order to ensure the operational safety. The requirements are in accordance with the international standards ISO 1677, ISO 2919, ISO 7205 and Nordic Recommendations on radiation protection for radionuclide gauges in permanent installation. The guide explains also the practical measures that must be taken into account when a radiation device is repaired, maintained or removed from the use. (8 refs.)

  7. Exposure of the Spanish population to radiation from natural sources

    International Nuclear Information System (INIS)

    Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L.

    2006-01-01

    We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value by a conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

  8. Exposure of the Spanish population to radiation from natural sources

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L. [Consejo de Seguridad Nuclear. Justo Dorado, Madrid (Spain)

    2006-07-01

    We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

  9. Radiation problems expected for the German spallation neutron source

    International Nuclear Information System (INIS)

    Goebel, K.

    1981-01-01

    The German project for the construction of a Spallation Neutron Source with high proton beam power (5.5 MW) will have to cope with a number of radiation problems. The present report describes these problems and proposes solutions for keeping exposures for the staff and release of activity and radiation into the environment as low as reasonably achievable. It is shown that the strict requirements of the German radiation protection regulations can be met. The main problem will be the exposure of maintenance personnel to remanent gamma radiation, as is the case at existing proton accelerators. Closed ventilation and cooling systems will reduce the release of (mainly short-lived) activity to acceptable levels. Shielding requirements for different sections are discussed, and it is demonstrated by calculations and extrapolations from experiments that fence-post doses well below 150 mrem/y can be obtained at distances of the order of 100 metres from the principal source points. The radiation protection system proposed for the Spallation Neutron Source is discussed, in particular the needs for monitor systems and a central radiation protection data base and alarm system. (orig.)

  10. The effect of multimicrophone noise reduction systems on sound source localization by users of binaural hearing aids.

    Science.gov (United States)

    Van den Bogaert, Tim; Doclo, Simon; Wouters, Jan; Moonen, Marc

    2008-07-01

    This paper evaluates the influence of three multimicrophone noise reduction algorithms on the ability to localize sound sources. Two recently developed noise reduction techniques for binaural hearing aids were evaluated, namely, the binaural multichannel Wiener filter (MWF) and the binaural multichannel Wiener filter with partial noise estimate (MWF-N), together with a dual-monaural adaptive directional microphone (ADM), which is a widely used noise reduction approach in commercial hearing aids. The influence of the different algorithms on perceived sound source localization and their noise reduction performance was evaluated. It is shown that noise reduction algorithms can have a large influence on localization and that (a) the ADM only preserves localization in the forward direction over azimuths where limited or no noise reduction is obtained; (b) the MWF preserves localization of the target speech component but may distort localization of the noise component. The latter is dependent on signal-to-noise ratio and masking effects; (c) the MWF-N enables correct localization of both the speech and the noise components; (d) the statistical Wiener filter approach introduces a better combination of sound source localization and noise reduction performance than the ADM approach.

  11. Dosimetric analysis of radiation sources for use dermatological lesions

    International Nuclear Information System (INIS)

    Tada, Ariane

    2010-01-01

    Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures . Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code were both physically consistent as expected. These experimental measurements compared with calculations using the MCNP-4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

  12. Personnel selection and training for radiation protection and safe use of radiation sources

    International Nuclear Information System (INIS)

    Gomaa, M.A.

    2000-01-01

    For proper implementation of the radiation protection programs in the work place, several persons with different qualifications and training are involved. Among these persons are regulatory personnel managers, operators, workers, health professional, health physics technicians, health physicists, qualified experts, and emergency personnel. The current status of education and training of these persons is discussed in order to build competence in radiation protection and the safe use of radiation sources

  13. ELBE Center for High-Power Radiation Sources

    Directory of Open Access Journals (Sweden)

    Peter Dr. Michel

    2016-01-01

    Full Text Available In the ELBE Center for High-Power Radiation Sources, the superconducting linear electron accelerator ELBE, serving  two free electron lasers, sources for intense coherent THz radiation, mono-energetic positrons, electrons, γ-rays, a neutron time-of-flight system as well as two synchronized ultra-short pulsed Petawatt laser systems are collocated. The characteristics of these beams make the ELBE center a unique research instrument for a variety of external users in fields ranging from material science over nuclear physics to cancer research, as well as scientists of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR.

  14. New sources of high-power coherent radiation

    International Nuclear Information System (INIS)

    Sprehngl, F.

    1985-01-01

    New sources of high-power coherent radiation in the wavelength range from millimeter to ultraviolet are reviewed. Physical mechanisms underlying concepts of free electrons laser, cyclotron resonance laser and other new radiation sources are described. Free electron lasers and cyclotron resonance lasers are shown to suggest excellent possibilities for solving problems of spectroscopy, plasma heating radar and accelerator technology. Results of experiments with free electron laser in the Compton mode using linear accelerators microtrons and storage rings are given. Trends in further investigations are shown

  15. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    Ritchie, A.; Oldfather, D.; Lindner, A.

    1993-05-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 GeV synchrotron light source facility consisting of a 120 keV electron gun, 50 MeV linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

  16. MCNP model for the many KE-Basin radiation sources

    International Nuclear Information System (INIS)

    Rittmann, P.D.

    1997-01-01

    This document presents a model for the location and strength of radiation sources in the accessible areas of KE-Basin which agrees well with data taken on a regular grid in September of 1996. This modelling work was requested to support dose rate reduction efforts in KE-Basin. Anticipated fuel removal activities require lower dose rates to minimize annual dose to workers. With this model, the effects of component cleanup or removal can be estimated in advance to evaluate their effectiveness. In addition, the sources contributing most to the radiation fields in a given location can be identified and dealt with

  17. Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection.

    Directory of Open Access Journals (Sweden)

    Andrew D Brown

    Full Text Available Hearing protection devices (HPDs such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement environments where auditory situational awareness is imperative. Here we assessed (1 sound source localization accuracy using a head-turning paradigm, (2 speech-in-noise recognition using a modified version of the QuickSIN test, and (3 tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive, including two new and previously untested devices. Relative to unoccluded (control performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions.

  18. Smart material-based radiation sources

    Science.gov (United States)

    Kovaleski, Scott

    2014-10-01

    From sensors to power harvesters, the unique properties of smart materials have been exploited in numerous ways to enable new applications and reduce the size of many useful devices. Smart materials are defined as materials whose properties can be changed in a controlled and often reversible fashion by use of external stimuli, such as electric and magnetic fields, temperature, or humidity. Smart materials have been used to make acceleration sensors that are ubiquitous in mobile phones, to make highly accurate frequency standards, to make unprecedentedly small actuators and motors, to seal and reduce friction of rotating shafts, and to generate power by conversion of either kinetic or thermal energy to electrical energy. The number of useful devices enabled by smart materials is large and continues to grow. Smart materials can also be used to generate plasmas and accelerate particles at small scales. The materials discussed in this talk are from non-centrosymmetric crystalline classes including piezoelectric, pyroelectric, and ferroelectric materials, which produce large electric fields in response to external stimuli such as applied electric fields or thermal energy. First, the use of ferroelectric, pyroelectric and piezoelectric materials for plasma generation and particle acceleration will be reviewed. The talk will then focus on the use of piezoelectric materials at the University of Missouri to construct plasma sources and electrostatic accelerators for applications including space propulsion, x-ray imaging, and neutron production. The basic concepts of piezoelectric transformers, which are analogous to conventional magnetic transformers, will be discussed, along with results from experiments over the last decade to produce micro-thrusters for space propulsion and particle accelerators for x-ray and neutron production. Support from ONR, AFOSR, and LANL.

  19. Radiation exposure management over a decade in sealed sources fabrication

    International Nuclear Information System (INIS)

    Chougule, Nitin V.; Swaminathan, N.; Singh, P.; Sreenivas, V.; Bairwa, S.M.; Rath, D.P.; Patil, B.N.; Sastry, K.V.S.

    2008-01-01

    Radioactive sealed sources find innumerable applications in medical and industrial applications. 60 Co teletherapy sources are used for the treatment of cancer. In brachytherapy; 137 Cs and 192 Ir are used. Industrial sources using 60 Co, 137 Cs find applications in nucleonic gauges, tracer studies etc. 60 Co and 192 Ir sources are used in radiography also. In addition, 60 Co is widely used in irradiator facilities. Board of Isotopes and Radiation Technology (BRIT) has committed in supply of these sealed sources to various hospitals and industrial institutions in India. Annually, PetaBq (PBq) level of above mentioned isotopes are handled remotely in hot cells, RLG, BARC. This paper brings out a detailed account on the radiological surveillance provided during the fabrication of these sources implementing ALARA. The decrease in collective dose per activity handled is the outcome of improved operation practices which were carried out at various stages of source fabrication. (author)

  20. The international standard for protection from ionizing radiation and safety of radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, T [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1995-06-01

    This document is a review in hebrew of the new 1994 international standard of the IAEA. The new standard title is `Basic safety standards for radiation protection and for the safety of radiation sources`, which were published in the ICRP Pub. 9.

  1. Audio-Visual Fusion for Sound Source Localization and Improved Attention

    International Nuclear Information System (INIS)

    Lee, Byoung Gi; Choi, Jong Suk; Yoon, Sang Suk; Choi, Mun Taek; Kim, Mun Sang; Kim, Dai Jin

    2011-01-01

    Service robots are equipped with various sensors such as vision camera, sonar sensor, laser scanner, and microphones. Although these sensors have their own functions, some of them can be made to work together and perform more complicated functions. AudioFvisual fusion is a typical and powerful combination of audio and video sensors, because audio information is complementary to visual information and vice versa. Human beings also mainly depend on visual and auditory information in their daily life. In this paper, we conduct two studies using audioFvision fusion: one is on enhancing the performance of sound localization, and the other is on improving robot attention through sound localization and face detection

  2. Audio-Visual Fusion for Sound Source Localization and Improved Attention

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byoung Gi; Choi, Jong Suk; Yoon, Sang Suk; Choi, Mun Taek; Kim, Mun Sang [Korea Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Dai Jin [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2011-07-15

    Service robots are equipped with various sensors such as vision camera, sonar sensor, laser scanner, and microphones. Although these sensors have their own functions, some of them can be made to work together and perform more complicated functions. AudioFvisual fusion is a typical and powerful combination of audio and video sensors, because audio information is complementary to visual information and vice versa. Human beings also mainly depend on visual and auditory information in their daily life. In this paper, we conduct two studies using audioFvision fusion: one is on enhancing the performance of sound localization, and the other is on improving robot attention through sound localization and face detection.

  3. Romanian experience on safety and security of radiation sources

    International Nuclear Information System (INIS)

    Botgros, Madalina; Coroianu, Anton; Negreanu, Mircea

    2008-01-01

    Romania has established the first administrative structure for controlling the deployment of the nuclear activities in 1961 and the first Romanian nuclear law was published in 1974. In the present, it is in force the Law no. 111, published in 1996 and republished in 2003. Moreover, there are available facilities and services to the persons authorized to manage radioactive sources. The regulation for safety and security of radioactive sources was amended two times in order to implement the international recommendations for setting up the national system for accounting and control of radiation sources and to coordinate the recovery activities. As part of national control programme, the national inventory of sources and devices is updated permanently, when issuing a new authorization, when modifying an existing one, or when renewing an authorization system and records in the database. The government responsibility for the orphan sources is stated in the law on radioactive waste management and decommissioning fund. There is a protocol between CNCAN, Ministry of Internal and Ministry of Health and Family regarding the co-operation in the case of finding orphan sources. When a radiation source is spent, it becomes radioactive waste that has to be disposed off properly. Depending on the case, the holder of a spent source has the possibility either to return the radioactive source to its manufacturer for regeneration or to transfer it to the Radioactive Waste Treatment Facility. (author)

  4. On the choice of working conditions for isotope radiation sources in irradiation plants

    International Nuclear Information System (INIS)

    Syrkus, N.P.; Breger, A.Kh.; Putilov, A.V.

    1975-01-01

    The problems of selecting an optimal regime for isotopic sources of radiation in powerful radiational installations depending on the costs, parameters of the radiational process (epsilon) and the radioactive isotope halflife are considered. When the radiation sources are simultaneusly replaced, then the optimal time of replacement of sources increases in the radiational installation with the radiation process parameter epsilon<0. Although the cost of a radiational product is lower during continuous replacement of radiation sources, the cost of products in the regime of simultaneous replacement of sources can be decreased, particularly, in the case of a secondary use of the radiactive sources

  5. Control of Sound Radiation and Reflection With Advanced Smart Foam Blankets

    National Research Council Canada - National Science Library

    Fuller, Chris

    2003-01-01

    .... The past few years of the project have demonstrated the high potential of using smart foam blankets for efficiently reducing the interior sound levels in the payloads of launch vehicles in the low...

  6. The German radiation protection infrastructure with emphasis on the safety of radiation sources and radioactive material

    International Nuclear Information System (INIS)

    Czarwinski, R.; Weimer, G.

    2001-01-01

    Through federalism, Germany has a complicated but well functioning regulatory infrastructure for the safety and security of radiation sources based on a clear legal system. The main features of this infrastructure include the legal framework, the authorization and control systems and the responsibilities of different regulatory authorities, which this paper will describe. In connection with the legal framework, the provisions to control the import/export of radiation sources are briefly discussed and some information is given about the registries of sources. Protection and response measures related to unusual events concerning radiation sources, including orphan sources, will be cited. Also, the education and training of different target groups and punitive actions are touched upon in the paper. Conclusions will be drawn for future national and international actions. (author)

  7. Potential sources for the radiation treatment of food

    International Nuclear Information System (INIS)

    Sande, W.E.; Libby, R.A.

    1976-01-01

    The present, near-term, and potential (through year 2000) supply of radiation sources for large-scale radiosterilization applications is discussed. Principal sources considered are 60 Co produced in nuclear power reactors, 137 Cs presently available from ERDA encapsulation operations, and a mixture of 134 Cs- 137 Cs potentially available from the reprocessing of spent nuclear fuel. Some consideration is also given to electron accelerators

  8. Impurity radiation from a beam-plasma neutron source

    International Nuclear Information System (INIS)

    Molvik, A.W.

    1995-01-01

    Impurity radiation, in a worst case evaluation for a beam-plasma neutron source (BPNS), does not limit performance. Impurities originate from four sources: (a) sputtering from walls by charge exchange or alpha particle bombardment, (b) sputtering from limiters, (c) plasma desorption of gas from walls and (d) injection with neutral beams. Sources (c) and (d) are negligible; adsorbed gas on the walls of the confinement chamber and the neutral beam sources is removed by the steady state discharge. Source (b) is negligible for impinging ion energies below the sputtering threshold (T i ≤ 0.025 keV on tungsten) and for power densities to the limiter within the capabilities of water cooling (30-40 MW/m 2 ); both conditions can be satisfied in the BPNS. Source (a) radiates 0.025 MW/m 2 to the neutron irradiation samples, compared with 5 to 10 MW/m 2 of neutrons; and radiates a total of 0.08 MW from the plasma column, compared with 60 MW of injected power. The particle bombardment that yields source (a) deposits an average of 2.7 MW/m 2 on the samples, within the capabilities of helium gas cooling (10 MW/m 2 ). An additional worst case for source (d) is evaluated for present day 2 to 5 s pulsed neutral beams with 0.1% impurity density and is benchmarked against 2XIIB. The total radiation would increase a factor of 1.5 to ≤ 0.12 MW, supporting the conclusion that impurities will not have a significant impact on a BPN. (author). 61 refs, 7 figs, 2 tabs

  9. Management of Spent and Disused Radiation Sources - The Zambian Experience

    International Nuclear Information System (INIS)

    Chabala, F.

    2002-01-01

    Zambia like all other countries in the world is faced with environmental problems brought about by a variety of human activities. In Zambia the major environmental issues as identified by Nation Environmental Action Plan (NEAP) of 1994 are water pollution, poor sanitation, land degradation, air pollution, poor waste management, misuse of chemicals, wildlife depletion and deforestation. Zambian has been using a lot of radioactive materials in its various industries. The country has taken several projects with help of external partners. These partners however left these projects in the hands of the Zambians without developing their capacities to manage these radioactive sources. The Government recognized the need to manage these sources and passed legislation governing the management of radioactive materials. The first act of Parliament on Radiation Protection work was passed in 1975 to legislate the use of ionizing radiation. However, because of financial constraints the Country is facing, these regulations have remained unimplemented. Fortunately the international Community has been working in partnership with the Zambian Government in the Management of Radioactive Material. Therefore this paper will present the following aspects of radioactive waste management in Zambia: review Existing Legislation in Zambia regarding management of spent/radioactive sources; capacity building in the field of management of radioactive waste; management of spent and disused radiation sources; existing disposal systems in Zambia regarding spent/orphaned sources; existing stocks of radioactive sources in the Zambian industries

  10. Analysis of polymer foil heaters as infrared radiation sources

    International Nuclear Information System (INIS)

    Witek, Krzysztof; Piotrowski, Tadeusz; Skwarek, Agata

    2012-01-01

    Infrared radiation as a heat source is used in many fields. In particular, the positive effect of far-infrared radiation on living organisms has been observed. This paper presents two technological solutions for infrared heater production using polymer-silver and polymer-carbon pastes screenprinted on foil substrates. The purpose of this work was the identification of polymer layers as a specific frequency range IR radiation sources. The characterization of the heaters was determined mainly by measurement of the surface temperature distribution using a thermovision camera and the spectral characteristics were determined using a special measuring system. Basic parameters obtained for both, polymer silver and polymer carbon heaters were similar and were as follows: power rating of 10–12 W/dm 2 , continuous working surface temperature of 80–90 °C, temperature coefficient of resistance (TCR) about +900 ppm/K for polymer-carbon heater and about +2000 ppm/K for polymer-silver, maximum radiation intensity in the wavelength range of 6–14 μm with top intensity at 8.5 μm and heating time about 20 min. For comparison purposes, commercial panel heater was tested. The results show that the characteristics of infrared polymer heaters are similar to the characteristics of the commercial heater, so they can be taken into consideration as the alternative infrared radiation sources.

  11. A holistic approach to hydrocarbon source allocation in the subtidal sediments of Prince William Sound, Alaska, embayments

    International Nuclear Information System (INIS)

    Page, D.S.; Bence, A.E.; Burns, W.A.; Boehm, P.D.; Brown, J.S.; Douglas, G.S.

    2002-01-01

    The complex organic geochemistry record in the subtidal sediments of Prince William Sound, Alaska is a result of much industrial and human activity in the region. Recent oil spills and a regional background of natural petroleum hydrocarbons originating from active hydrocarbon systems in the northern Gulf of Alaska also contribute to the geochemical record. Pyrogenic and petrogenic polycyclic aromatic hydrocarbons (PAH) are introduced regularly to the subtidal sediments at sites of past and present human activities including villages, fish hatcheries, fish camps and recreational campsites as well as abandoned settlements, canneries, sawmills and mines. Hydrocarbon contributions are fingerprinted and quantified using a holistic approach where contributions from multiple sources is determined. The approach involves a good understanding of the history of the area to identify potential sources. It also involves extensive collection of representative samples and an accurate quantitative analysis of the source and sediment samples for PAH analytes and chemical biomarker compounds. Total organic carbon (TOC) does not work in restricted embayments because of a constrained least-square algorithm to determine hydrocarbon sources. It has been shown that sources contributing to the natural petrogenic background are present in Prince William Sound. In particular, pyrogenic hydrocarbons such as combustion products of diesel is significant where there was much human activity. In addition, petroleum produced from the Monterey Formation in California is present in Prince William Sound because in the past, oil and asphalt shipped from California was widely used for fuel. Low level residues of weathered Alaskan North Slope crude oil from the Exxon Valdez spill are also still present. 30 refs., 4 tabs., 2 figs

  12. Insights into Optimal Soft Start and Shutdown Procedures for Stationary or Moving Sound Sources

    NARCIS (Netherlands)

    Ainslie, M.A.; Benda-Beckmann, A.M. von

    2012-01-01

    To reduce the risk of impact on marine life of underwater sound generated by anthropogenic activities (such as offshore construction, seismic surveys and sonar searches), various mitigation measures are often put in place. Two commonly adopted mitigation measures are the soft start (or "ramp-up" –

  13. Ultrabroadband terahertz source and beamline based on coherent transition radiation

    Directory of Open Access Journals (Sweden)

    S. Casalbuoni

    2009-03-01

    Full Text Available Coherent transition radiation (CTR in the THz regime is an important diagnostic tool for analyzing the temporal structure of the ultrashort electron bunches needed in ultraviolet and x-ray free-electron lasers. It is also a powerful source of such radiation, covering an exceptionally broad frequency range from about 200 GHz to 100 THz. At the soft x-ray free-electron laser FLASH we have installed a beam transport channel for transition radiation (TR with the intention to guide a large fraction of the radiation to a laboratory outside the accelerator tunnel. The radiation is produced on a screen inside the ultrahigh vacuum beam pipe of the linac, coupled out through a diamond window and transported to the laboratory through an evacuated tube equipped with five focusing and four plane mirrors. The design of the beamline has been based on a thorough analysis of the generation of TR on metallic screens of limited size. The optical propagation of the radiation has been computed taking into account the effects of near-field (Fresnel diffraction. The theoretical description of the TR source is presented in the first part of the paper, while the design principles and the technical layout of the beamline are described in the second part. First experimental results demonstrate that the CTR beamline covers the specified frequency range and preserves the narrow time structure of CTR pulses emitted by short electron bunches.

  14. Prediction of radiation ratio and sound transmission of complex extruded panel using wavenumber domain Unite element and boundary element methods

    International Nuclear Information System (INIS)

    Kim, H; Ryue, J; Thompson, D J; Müller, A D

    2016-01-01

    Recently, complex shaped aluminium panels have been adopted in many structures to make them lighter and stronger. The vibro-acoustic behaviour of these complex panels has been of interest for many years but conventional finite element and boundary element methods are not efficient to predict their performance at higher frequencies. Where the cross-sectional properties of the panels are constant in one direction, wavenumber domain numerical analysis can be applied and this becomes more suitable for panels with complex cross-sectional geometries. In this paper, a coupled wavenumber domain finite element and boundary element method is applied to predict the sound radiation from and sound transmission through a double-layered aluminium extruded panel, having a typical shape used in railway carriages. The predicted results are compared with measured ones carried out on a finite length panel and good agreement is found. (paper)

  15. Mapping of auroral kilometric radiation sources to the aurora

    International Nuclear Information System (INIS)

    Huff, R.L.; Calvert, W.; Craven, J.D.; Frank, L.A.; Gurnett, D.A.

    1988-01-01

    Auroral kilometric radiation (AKR) and optical auroral emissions are observed simultaneously using plasma wave instrumentation and auroral imaging photometers acrried on the DE 1 spacecraft. The DE 1 plasma wave instrument measures the relative phase of signals from orthogonal electric dipole antennas, and from these measurements, apparent source directions can be determined with a high degree of precision. Wave data are analyzed for several strong AKR events, and source directions are determined for several emission frequencies. By assuming that the AKR originates at cyclotron resonant altitudes, a condidate source field line is identified. When the selected source field line is traced down to auroral altitudes on the concurrent DE 1 auroral image, a striking correspondence between the AKR source field line and localized auroral features is produced. The magnetic mapping study provides strong evidence that AKR sources occur on field lines associated with discrete auroral arcs, and it provides confirmation that AKR is generated near the electron cyclotron frequency

  16. Overview in Argentina on spent/disused radiation sources

    International Nuclear Information System (INIS)

    Lavalle, M.B.

    2001-01-01

    Argentine nuclear activities have begun since about 1950. Since those days the peaceful applications of nuclear energy have been developed and together with then radioactive wastes have taken more and more relevance day by day. To deal with this special subject the Radioactive Waste Management Programme (RWMP) has been established. Spent/disused radiation sources are a very important task to consider in the management of radioactive waste. A great number of sources have been received along these years by the RWMP. Different sources categories handled together with their figures and radionuclide activities will be presented. Also described will be the steps that have to be followed by the users/owners of spent/disused radiation sources to transfer them to the RWMP. Once the sources are in the RWMP custody, they can be stored or they can be conditioned in order to be stored in an interim storage or disposed of. It is shown how the different sources are managed, taking into account the radionuclide's half life, its activity and the available facilities. Besides a record-keeping system for tracking all spent/disused radiation sources has been developed. It consists on a computerized database that contains essential information about the sources as well as the whole radioactive wastes managed by the RWMP. The main objective of the waste management registry-database system is to collect, identify, process and follow the related information about the radioactive wastes among al the management steps. It is also able to calculate the actualized activity inventory for the storage and final disposal facilities. In order to implement this system, it was necessary to write the related technical documentation. These documents established the radioactive waste acceptance requirements, that together with others integrates the Quality Assurance System applied to the radioactive waste management. Regarding the disused sources little could be done. They are stored in an appropriate

  17. International basic safety standards for protecting against ionizing radiation and for the safety of radiation sources

    International Nuclear Information System (INIS)

    1997-01-01

    The purpose of the Standards is to establish basic requirements for protection against the risks associated with exposure to ionizing radiation (hereinafter termed radiation) and for the safety of radiation sources that may deliver such exposure. The Standards have been developed from widely accepted radiation protection and safety principles, such as those published in the Annals of the ICRP and the IAEA Safety Series. They are intended to ensure the safety of all types of radiation sources and, in doing so, to complement standards already developed for large and complex radiation sources, such as nuclear reactors and radioactive waste management facilities. For the sources, more specific standards, such as those issued by the IAEA, are typically needed to achieve acceptable levels of safety. As these more specific standards are generally consistent with the Standards, in complying with them, such more complex installations will also generally comply with the Standards. The Standards are limited to specifying basic requirements of radiation protection and safety, with some guidance on how to apply them. General guidance on applying some of the requirements is available in the publications of the Sponsoring Organizations and additional guidance will be developed as needed in the light of experience gained in the application of the Standards

  18. International basic safety standards for protecting against ionizing radiation and for the safety of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    The purpose of the Standards is to establish basic requirements for protection against the risks associated with exposure to ionizing radiation (hereinafter termed radiation) and for the safety of radiation sources that may deliver such exposure. The Standards have been developed from widely accepted radiation protection and safety principles, such as those published in the Annals of the ICRP and the IAEA Safety Series. They are intended to ensure the safety of all types of radiation sources and, in doing so, to complement standards already developed for large and complex radiation sources, such as nuclear reactors and radioactive waste management facilities. For the sources, more specific standards, such as those issued by the IAEA, are typically needed to achieve acceptable levels of safety. As these more specific standards are generally consistent with the Standards, in complying with them, such more complex installations will also generally comply with the Standards. The Standards are limited to specifying basic requirements of radiation protection and safety, with some guidance on how to apply them. General guidance on applying some of the requirements is available in the publications of the Sponsoring Organizations and additional guidance will be developed as needed in the light of experience gained in the application of the Standards. Tabs

  19. Sources of ionizing radiation in industry: licensing and control

    International Nuclear Information System (INIS)

    Dimitrov, V.

    2001-01-01

    In this paper are presented several methods, which the Inspection on the Safe Use of Atomic Energy applies for the control on the use of sources of ionizing radiation in industry. It reviews some problems, which we have to solve during our inspections. An analysis and assessment of them is done. The prescribed safety ensuring measures are discussed. (author)

  20. Review of radiation sources, calibration facilities and simulated workplace fields

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, V., E-mail: veronique.lacoste@irsn.f [Institut de Radioprotection et de Surete Nucleaire, BP3, Bat. 159, F-13115 Saint-Paul Lez Durance (France)

    2010-12-15

    A review on radiation sources, calibration facilities and realistic fields is presented and examples are given. The main characteristics of the fields are shortly described together with their domain of applications. New emerging fields are also mentioned and the question of needs for additional calibration fields is raised.

  1. Experience with first aid in radiation sources accidents

    International Nuclear Information System (INIS)

    Klener, V.

    1979-01-01

    More than 20 years of experience at the Radiation Hygiene Centre of the Prague Institute of Hygiene and Epidemiology with prevention of accidents involving sources of radiation and the Centre's participation in providing medical aid in such accidents are described. A list is given of major types of accidents over the past decade. Prevalent were accidents involving sealed gamma sources, resulting in excessive local irradiation with serious skin damage or injury to some of the deeper structures of the hands, requiring plastic operation. Chromosomal picture investigation allows the estimation of the equivalent body dose which only reached higher values in a single case recorded (1.5 Gy = 150 rad). Organisational measures are described for emergencies and the task is shown by radiation hygiene departments attached to regional hygiene stations. The present system is capable of providing adequate, prompt and effective assistance. (author)

  2. Control of radiation sources and general regulations for accidental situations

    International Nuclear Information System (INIS)

    Slimani, A.

    1998-01-01

    In order to prevent accidents caused by application of radiation sources the Tunisian O.N.P.C. established straightforward strategy made up of 3 phases: prevention, planning and intervention. Civil Protection conducts prevention studies of all radiation sources by examining normal application conditions as well as possible accidental situations. It keeps up with scientific, technical and statistical aspects of radiation risks, elaborates specific plans and programs for intervention operations and cooperates with administrative and security services as well as international organisations. The O.N.P.C. established a model intervention plan based on observation (according to preliminary information), evaluation of the situation (according to the head of operation) intervention (specialized units) and post intervention (testing of personnel)

  3. Standard Syllabus for Postgraduate Educational Courses in Radiation Protection and the Safe use of Radiation Sources

    International Nuclear Information System (INIS)

    Arias, C.; Biaggio, A.; Nasazzi, N.

    2004-01-01

    The International Atomic Energy Agency (IAEA) published the Standard Syllabus for Post Graduate Educational Courses in Radiation Protection and the Safety of Radiation Sources in 2002. Along more than two decades, Argentina has obtained valuable experience on building professional knowledge at postgraduate level in Radiation Protection and Nuclear Safety. Such experience made advisable to review the IAEA Standard Syllabus and to modify it accordingly. The whole content of the Standard Syllabus is included in the syllabus developed for the Argentinean Regional Post Graduate Course in Radiation Protection and Safety of Radiation Sources. But a few additional topics were incorporated and changes were introduced in the sequence of subjects. The paper describes those modifications and explains the pedagogic motivations that induce them. (Author) 3 refs

  4. Doses arising from natural radiation sources in Hong Kong

    International Nuclear Information System (INIS)

    Tso Man-yin, W.

    1993-01-01

    The first reactor of the Daya Bay Nuclear Power Plant, located 30 km from Hong Kong, should become operational at the end of 1993. People in Hong Kong are more concerned with their exposures to radiation, both man-made and natural. The local environmental background radiation baseline values should be established well before 1993 so that the radiological impact of the power plant on the environment can be assessed. However, there has not been much information on these aspects. In view of the situation, the Radioisotope Unit of the University of Hong Kong has launched a series of studies with the general goal of gaining a better understanding of Hong Kong's natural background radiation and a more accurate estimate of the natural radiation exposure of the local people. The scope of the measurement programmes is described and the doses from the various sources are derived. (1 tab.)

  5. Earth as a radio source: terrestrial kilometric radiation. Progress report

    International Nuclear Information System (INIS)

    Gurnett, D.A.

    1974-02-01

    Radio wave experiments on the IMP-6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range from about 50 kHz to 500 kHz. A peak intensity the total power emitted in this frequency range is about 1 billion watts. The earth is, therefore, a very intense planetary radio source, with a total power output comparable to the decametric radio emission from Jupiter. This radio emission from the earth is referred to as terrestrial kilometric radiation. Terrestrial kilometric radiation appears to originate from low altitudes (less than 3.0 Re) in the auroral region. Possible mechanisms which can explain the generation and propagation of the terrestrial kilometric radiation are discussed. (U.S.)

  6. The handling with orphan sources of ionizing radiation in Belarus

    International Nuclear Information System (INIS)

    Dubrovskij, A.I.; Beresneva, V.A.; Pribylev, S.V.

    2013-01-01

    In Belarus, the emergency response actions, when detecting orphan sources, provide specific organs of government within their competence. Overall coordination and work on the collection, processing, exchange, accounting and transfer in the established order information about the sources of ionizing radiation interacting organs and relevant international organizations assigned to the Emergency Situations Ministry. Created in Belarus response system in case of detection of orphan sources can provide the level of emergency preparedness and response, and generally satisfy international best practice in this area. (authors)

  7. Small compact pulsed electron source for radiation technologies

    International Nuclear Information System (INIS)

    Korenev, Sergey

    2002-01-01

    The small compact pulsed electron source for radiation technologies is considered in the report. The electron source consists of pulsed high voltage Marx generator and vacuum diode with explosive emission cathode. The main parameters of electron source are next: kinetic energy is 100-150 keV, beam current is 5-200 A and pulse duration is 100-400 nsec. The distribution of absorbed doses in irradiated materials is considered. The physical feasibility of pulsed low energy electron beam for applications is considered

  8. Nuisance Source Population Modeling for Radiation Detection System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sokkappa, P; Lange, D; Nelson, K; Wheeler, R

    2009-10-05

    A major challenge facing the prospective deployment of radiation detection systems for homeland security applications is the discrimination of radiological or nuclear 'threat sources' from radioactive, but benign, 'nuisance sources'. Common examples of such nuisance sources include naturally occurring radioactive material (NORM), medical patients who have received radioactive drugs for either diagnostics or treatment, and industrial sources. A sensitive detector that cannot distinguish between 'threat' and 'benign' classes will generate false positives which, if sufficiently frequent, will preclude it from being operationally deployed. In this report, we describe a first-principles physics-based modeling approach that is used to approximate the physical properties and corresponding gamma ray spectral signatures of real nuisance sources. Specific models are proposed for the three nuisance source classes - NORM, medical and industrial. The models can be validated against measured data - that is, energy spectra generated with the model can be compared to actual nuisance source data. We show by example how this is done for NORM and medical sources, using data sets obtained from spectroscopic detector deployments for cargo container screening and urban area traffic screening, respectively. In addition to capturing the range of radioactive signatures of individual nuisance sources, a nuisance source population model must generate sources with a frequency of occurrence consistent with that found in actual movement of goods and people. Measured radiation detection data can indicate these frequencies, but, at present, such data are available only for a very limited set of locations and time periods. In this report, we make more general estimates of frequencies for NORM and medical sources using a range of data sources such as shipping manifests and medical treatment statistics. We also identify potential data sources for industrial

  9. Research sources of ionizing radiation based on transplutonium elements

    Science.gov (United States)

    Radchenko, V. M.; Ryabinin, M. A.

    2010-03-01

    Scientific and technical demand stimulates an extension of the practical implementation field of TPE, requirements to their ecological safety calling for the development of such materials which could be most resistant to the environment and most suitable for the production of a wide range of sources different in their application and design. Such materials can involve pure metals of transplutonium elements and their alloys with metals of platinum group as well as their chemically stable compounds (such as silicides, carbides etc.) At SSC RIAR production processes of sources of different type and application have been implemented. Examples of the most recent developments of the sources are presented below. Presented is the analysis of the current state of issues related to designing, production and application of radionuclide research sources based on transplutonium elements. Examples of the development of the most up-to-date sources of alpha-, gamma- and neutron radiation and also fission ones are considered.

  10. Spectral and temporal cues for perception of material and action categories in impacted sound sources

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; McAdams, Stephen

    2016-01-01

    In two experiments, similarity ratings and categorization performance with recorded impact sounds representing three material categories (wood, metal, glass) being manipulated by three different categories of action (drop, strike, rattle) were examined. Previous research focusing on single impact...... correlated with the pattern of confusion in categorization judgments. Listeners tended to confuse materials with similar spectral centroids, and actions with similar temporal centroids and onset densities. To confirm the influence of these different features, spectral cues were removed by applying...

  11. Training in radiation protection and the safe use of radiation sources

    International Nuclear Information System (INIS)

    2001-01-01

    The need for education and training in the various disciplines of radiation protection has long been recognized by the IAEA, the International Labour Organization (ILO), the United Nations Educational, Scientific and Cultural Organization, the World Health Organization and the Pan American Health Organization (PAHO). This need has been partially met through the many training courses undertaken by these organizations, either individually or in collaboration. The IAEA has assisted developing Member States in the training of specialists in radiation protection and safety through its organized educational and specialized training courses, workshops, seminars, fellowships and scientific visits. Training is an important means of promoting safety culture and enhancing the level of competence of personnel involved in radiation protection activities, and has acquired a place in the IAEA's programme accordingly. For example, the IAEA Post-graduate Educational Course in Radiation Protection and the Safe Use of Radiation Sources is regularly offered in countries around the world, and has been provided in Arabic, English, French, Spanish and Russian. The training provided by the IAEA is primarily aimed at regulators, professionals working in radiation protection and those responsible for the development of training programmes in their own countries. The importance of adequate and appropriate training for all those working with ionizing radiation has been highlighted by the results of the IAEA's investigations of radiological accidents. A significant contributory factor in a number of the accidents has been a lack of adequate training, which gave rise to errors with serious consequences. This report provides assistance in organizing training and complying with the requirements on training of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS). The previous version of this report. Technical Reports

  12. Definition of loss-of-coolant accident radiation source

    International Nuclear Information System (INIS)

    1978-02-01

    Meaningful qualification testing of nuclear reactor components requires a knowledge of the radiation fields expected in a loss-of-coolant accident (LOCA). The overall objective of this program is to define the LOCA source terms and compare these with the output of various simulators employed for radiation qualification testing. The basis for comparison will be the energy deposition in a model reactor component. The results of the calculations are presented and some interpretation of the results given. The energy release rates and spectra were validated by comparison with other calculations using different codes since experimental data appropriate to these calculations do not exist

  13. Area radiation monitor at the intense pulsed-neutron source

    International Nuclear Information System (INIS)

    Eichholz, J.J.; Lynch, F.J.; Mundis, R.L.; Howe, M.L.; Dolecek, E.H.

    1981-01-01

    A tissue-equivalent ionization chamber with associated circuitry has been developed for area radiation monitoring in the Intense Pulsed-Neutron Source (IPNS) facility at Argonne National Laboratory. The conventional chamber configuration was modified in order to increase the electric field and effective volume thereby achieving higher sensitivity and linearity. The instrument provides local and remote radiation level indications and a high level alarm. Twenty-four of these instruments were fabricated for use at various locations in the experimental area of the IPNS-1 facility

  14. Programmes and Systems for Source and Environmental Radiation Monitoring

    International Nuclear Information System (INIS)

    2010-01-01

    The discharge of radionuclides to the atmosphere and aquatic environments is a legitimate practice in the nuclear and other industries, hospitals and research. Where appropriate, monitoring of the discharges and of relevant environmental media is an essential regulatory requirement in order to ensure appropriate radiation protection of the public. Such monitoring provides information on the actual amounts of radioactive material discharged and the radionuclide concentrations in the environment, and is needed to demonstrate compliance with authorized limits, to assess the radiation exposure of members of the public and to provide data to aid in the optimization of radiation protection. Uncontrolled releases of radionuclides to the atmosphere and aquatic environments may occur as a result of a nuclear or radiological accident. Again, monitoring at the source of the release and of the environment is necessary. In this case, monitoring is used both to assess the radiation exposure of members of the public and to determine the actions necessary for public protection, including longer term countermeasures. Source and environmental monitoring associated with the release of radionuclides to the environment is the subject of a number of IAEA Safety Standards, particularly IAEA Safety Standard RS-G-1.8 (Environmental and Source Monitoring for Purposes of Radiation Protection). This publication is intended to complement this Safety Guide and, by so doing, replaces Safety Series No. 41 (Objectives and Design of Environmental Monitoring Programmes for Radioactive Contaminants) and Safety Series No. 46 (Monitoring of Airborne and Liquid Radioactive Releases from Nuclear Facilities to the Environment). Like Safety Standard RS-G-1.8, this Safety Report deals with monitoring at the source and in the environment associated with authorized releases of radionuclides to the environment. It also deals with the general issues of emergency monitoring during and in the aftermath of an

  15. Overview of physical safety of radiation sources in Brazil

    International Nuclear Information System (INIS)

    Lima, A.R.; Silva, F.C.A. da

    2017-01-01

    The threat of 'radiological terrorism' has been recognized worldwide after the event of September 11, 2001. Radioactive sources can be used for the development of DDR ('dirty bomb') devices. Studies show that the use of a DDR could cause health damage, psychosocial and economic and environmental damage. Brazil follows this worldwide concern, since it has a large medical-industrial park that uses radioactive sources. This paper presents an overview of the physical safety of radioactive sources in Brazil, based on the inventory of radiative facilities, regulatory aspects and international recommendations. For the preparation of the study, the database of radioactive sources of the regulatory body, the current normative status and the international recommendations were used. In Brazil there are approximately 2,500 radiative installations, with about 400 radioactive sources Category 1 and 2, which are the biggest concern in terms of physical safety. The Brazilian licensing standard addresses only some aspects of physical protection, not providing a clear orientation for the elaboration and implementation of physical protection systems, in accordance with international recommendations. For Brazil to be included in the world scenario of physical safety of radioactive sources, it is urgent to elaborate specific legislation with well-defined regulatory criteria. The lack of more detailed requirements makes it difficult to make a more careful regulatory assessment of the physical protection conditions of the facilities, either through the evaluation of plans and other physical protection documents or through regulatory inspections

  16. On Distributions of Emission Sources and Speed-of-Sound in Proton-Proton (Proton-Antiproton Collisions

    Directory of Open Access Journals (Sweden)

    Li-Na Gao

    2015-01-01

    Full Text Available The revised (three-source Landau hydrodynamic model is used in this paper to study the (pseudorapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. The central source is assumed to contribute with a Gaussian function which covers the rapidity distribution region as wide as possible. The target and projectile sources are assumed to emit isotropically particles in their respective rest frames. The model calculations obtained with a Monte Carlo method are fitted to the experimental data over an energy range from 0.2 to 13 TeV. The values of the squared speed-of-sound parameter in different collisions are then extracted from the width of the rapidity distributions.

  17. Radiation exposure by monitors and effects of whistling sound on hearing at workplaces in TV and film production sectors

    International Nuclear Information System (INIS)

    Strasser, H.

    1988-01-01

    Information transmission by means of VDUs, spreading at present rapidly in office work and some branches of the industrial production, is not only an auxiliary means but the essential destination and objective of working activities in specific areas of the media sector. By the progression of the video technique a further concentration of VDT work and the increasing gravity of all advantages and disadvantages is to be expected in the film and TV sectors. The real radiation exposure of the technical staff involved in working with and at monitors and potential risks of hearing by whistling sounds sent out by these apparatuses are analysed and evaluated. Experiences in health hazards by radiation from VDUs in office work had to be adapted adequately to the specific working conditions at work places in film and TV productions. (orig./HP) [de

  18. Radiological protection issues in endovascular use of radiation sources

    International Nuclear Information System (INIS)

    2006-02-01

    The use of radiation from radioactive materials for cancer treatment is well established. However, examples of uses of radiation therapy for benign conditions have been limited. Placing a radioactive source in the blood vessel so as to irradiate the surrounding inner periphery of the vessel has been attempted in recent years to prevent restenosis after percutaneous coronary and peripheral interventions. This kind of endovascular application provides treatment options that are less invasive for various vascular conditions compared with open surgery. As a part of the International Atomic Energy Agency's (IAEA) function for providing for application of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) that were jointly sponsored by the IAEA, FAO, ILO, OECD/NEA, PAHO and WHO, the IAEA planned a coordinated research project (CRP) that was to start in 2002 on radiological protection problems in endovascular use of radiation sources. However, as experts soon realized that the interest in this modality was waning, the CRP was not initiated. Nevertheless, it was felt that it would be appropriate to compile the information available on radiological protection problems observed so far and their possible solutions. This work was seen as part of a broader IAEA programme that covered accident prevention in radiotherapy. Publications on this topic have included, inter alia, Lessons Learned from Accidental Exposures in Radiotherapy (Safety Reports Series No. 17); Accidental Overexposure of Radiotherapy Patients in Bialystok; Investigation of an Accidental Exposure of Radiotherapy Patients in Panama; Accidental Overexposure of Radiotherapy Patients in San Jose, Costa Rica; and Investigation of an Accidental Exposure of Radiotherapy Patients in Poland. Keeping in mind that endovascular applications involve specialists such as cardiologists, angiologists and surgeons, all of whom might not have a

  19. Medical and industrial radiation sources as radiological weapons

    International Nuclear Information System (INIS)

    Bielefeld, T.; Fischer, H.W.

    2006-01-01

    The execution of attacks with radiological weapons are well within the capabilities of both local terrorist groups and transnational terrorist networks. In a research project, plausible attack scenarios have been developed, based on medical and industrial radioactive sources widely used in Germany. Special emphasis was put on how such sources could be obtained applying criminal tactics. To this end, working procedures in hospitals and companies have been analyzed. Furthermore, by means of simulations, the consequences of a terrorist attack using such sources were estimated. None of the scenarios we investigated led to doses at the site of the explosion which might cause acute radiation effects. However, in some scenarios, an attack would result in the necessity of a potentially very costly clean-up of large urban areas. Therefore, improvements in sources security are recommended. (orig.)

  20. Sources and effects of ionizing radiation. UNSCEAR 2000 report to the General Assembly, with scientific annexes. Volume I: Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Over the past few years the United Nations Scientific Committee on the effects of Atomic Radiation has undertaken a broad review of the sources and effects of ionizing radiation. In the present report, the Committee, drawing on the main conclusions of its scientific assessment summarizes the developments in radiation science in the years leading up to the next millennium. It covers the following: the effects of radiation exposure; levels of radiation exposure; radiological consequences of the Chernobyl accident; sources of radiation exposure including natural exposures, man-made environmental exposures, medical and occupational exposures; radiation associated cancer. This volume includes five Annexes covering: dose assessment methodologies; exposure from natural sources; exposures to the public from man-made sources of radiation and occupational radiation exposures

  1. Study of spear as a dedicated source of synchrotron radiation

    International Nuclear Information System (INIS)

    Cerino, J.; Golde, A.; Hastings, J.; Lindau, I.; Salsburg, B.; Winick, H.; Lee, M.; Morton, P.; Garren, A.

    1977-11-01

    A study was made of the potential of SPEAR as a dedicated source of synchrotron radiation, based on the expectation that SPEAR will become increasingly available for this purpose as PEP, the 18-GeV colliding-beam storage ring now under construction by LBL and SLAC, becomes operational. A synchrotron radiation research program has been underway since May, 1974. Two beam ports capable of serving 9 simultaneous users are now operational. In single-beam multi-bunch operation high currents are possible (225 mA has been achieved and > approximately 300 mA is expected) and the electron beam emittance can be made smaller, resulting in higher source point brightness. Descriptions are given of SPEAR capabilities and of plans to expand the research capability by adding beam runs and by inserting wiggler magnets in SPEAR straight sections

  2. Regulatory control of radiation sources in the Philippines

    International Nuclear Information System (INIS)

    Daroy, Rosita R.

    1995-01-01

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

  3. Science experiments via telepresence at a synchrotron radiation source facility

    International Nuclear Information System (INIS)

    Warren, J. E.; Diakun, G.; Bushnell-Wye, G.; Fisher, S.; Thalal, A.; Helliwell, M.; Helliwell, J. R.

    2008-01-01

    The application of a turnkey communication system for telepresence at station 9.8 of the Synchrotron Radiation Source, Daresbury, is described and demonstrated, including its use for inter-continental classroom instruction and user training. Station 9.8 is one of the most oversubscribed and high-throughput stations at the Synchrotron Radiation Source, Daresbury, whereby awarded experimental time is limited, data collections last normally no longer than an hour, user changeover is normally every 24 h, and familiarity with the station systems can be low. Therefore time lost owing to technical failures on the station has a dramatic impact on productivity. To provide 24 h support, the application of a turnkey communication system has been implemented, and is described along with additional applications including its use for inter-continental classroom instruction, user training and remote participation

  4. System for selection of radiation source transfer trucks

    International Nuclear Information System (INIS)

    Tanimoto, Yoshinori; Ito, Kojiro.

    1970-01-01

    A device for selection of trucks each of which load and transfer a radiation source to an irradiation room above a water pool is installed at the end of a pair of rails fixed to the bottom of the pool. This device is equipped with a number of laterally shiftable rail pairs which may be brought into successive alignment with the fixed rails and is adapted to receive, carry and fix a truck on each rail pair. If one of said trucks is selected for irradiation in a desired irradiation room, the rail pair carrying this truck is shifted to align and couple with the fixed rail pair whereupon the truck is driven and transferred to a position on the fixed rails below the desired room and elevated thereinto. Accordingly, a plurality of trucks can optionally be shunted on a line of fixed rails without unloading the respective radiation sources. (Ohno, Y.)

  5. Radiation Parameters of High Dose Rate Iridium -192 Sources

    Science.gov (United States)

    Podgorsak, Matthew B.

    A lack of physical data for high dose rate (HDR) Ir-192 sources has necessitated the use of basic radiation parameters measured with low dose rate (LDR) Ir-192 seeds and ribbons in HDR dosimetry calculations. A rigorous examination of the radiation parameters of several HDR Ir-192 sources has shown that this extension of physical data from LDR to HDR Ir-192 may be inaccurate. Uncertainty in any of the basic radiation parameters used in dosimetry calculations compromises the accuracy of the calculated dose distribution and the subsequent dose delivery. Dose errors of up to 0.3%, 6%, and 2% can result from the use of currently accepted values for the half-life, exposure rate constant, and dose buildup effect, respectively. Since an accuracy of 5% in the delivered dose is essential to prevent severe complications or tumor regrowth, the use of basic physical constants with uncertainties approaching 6% is unacceptable. A systematic evaluation of the pertinent radiation parameters contributes to a reduction in the overall uncertainty in HDR Ir-192 dose delivery. Moreover, the results of the studies described in this thesis contribute significantly to the establishment of standardized numerical values to be used in HDR Ir-192 dosimetry calculations.

  6. Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Wang, Hailong [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Smith, Steven J. [Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park MD USA; Easter, Richard C. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Rasch, Philip J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA

    2018-02-08

    Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burden are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.

  7. Starting material radiation source for Moessbauer investigations of tellurium compounds

    International Nuclear Information System (INIS)

    Alexandrov, A.J.; Grushko, J.S.; Makarov, E.F.; Mishin, K.Y.; Baltrunas, D.A.J.

    1977-01-01

    A method is described of preparing a radiation source for Mossbauer investigations of tellurium compounds manufactured on the basis of 5 MgO . Te 124 O 3 . 5 MgO . Te 124 O 3 is irradiated in a reactor by means of thermal neutrons, followed by annealing at a temperature ranging from 600 0 to 1,100 0 C for a period of from 5 to 10 hours

  8. Experiments planned to be made with the synchrotron radiation source

    International Nuclear Information System (INIS)

    Matz, W.

    1993-01-01

    For this working meeting, various research groups from the Land Sachsen and from the neighbouring countries Poland and the Czech Republic have been invited in order to present their materials research programmes or task-specific experiments intended to be carried out with the synchrotron radiation source to be installed in the near future. The proceedings volume in hand presents the discussion papers, which have been directly reproduced from the original foils. (orig.) [de

  9. Limitation of population's irradiation by natural sources of ionizing radiation

    International Nuclear Information System (INIS)

    Krisyuk, Eh.M.

    1989-01-01

    Review of works devoted to evaluating the human irradiation doses at the expense of the main sources of ionizing radiation, is given. It is shown that the human irradiation doses at the expense of DDP can be reduced 10 times and more. However to realize such measures it is necessary to study the efficiency and determine the cost of various protective activities as well as to develop the criteria of their realization necessity

  10. Sound field separation with sound pressure and particle velocity measurements

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn; Leclère, Quentin

    2012-01-01

    separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure...... and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance......In conventional near-field acoustic holography (NAH) it is not possible to distinguish between sound from the two sides of the array, thus, it is a requirement that all the sources are confined to only one side and radiate into a free field. When this requirement cannot be fulfilled, sound field...

  11. Regulatory control of radiation sources in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Daroy, Rosita R

    1996-12-31

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI`s regulatory functions are presented. (author). Paper presented during the IAEA Regional (RCA) Workshop on System of Notification, Registration, Licensing, and Control of Radiation Sources and Installations, Jakarta, Indonesia, 24-28 April 1995. 6 refs., 2 figs., 12 tabs.

  12. Technological challenges of third generation synchrotron radiation sources

    International Nuclear Information System (INIS)

    Cornacchia, M.; Winick, H.

    1990-01-01

    New ''third generation'' synchrotron radiation research facilities are now in construction in France, Italy, Japan, Taiwan and the USA. Designs for such facilities are being developed in several other countries. Third generation facilities are based on storage rings with low electron beam emittance and space for many undulator magnets to produce radiation with extremely high brightness and coherent power. Photon beam from these rings will greatly extend present research capabilities and open up new opportunities in imaging, spectroscopy, structural and dynamic studies and other applications. The technological problems of the third generation of synchrotron radiation facilities are reviewed. These machines are designed to emit radiation of very high intensity, extreme brightness, very short pulses, and partial coherence. These performance goals put severe requirements on the quality of the electron or positron beams. Phenomena affecting the injection process and the beam lifetime are discussed. Gas desorption by synchrotron radiation and collective effects play an important role. Low emittance lattices are more sensitive to quadrupole movements and at the same time, in order not to lose the benefits of high brilliance, require tighter tolerances on the allowed movement of the photon beam source. We discuss some of the ways that should be considered to extend the performance capabilities of the facilities in the future. 14 refs., 1 fig

  13. Risks and hazards from conventional and radiation sources

    International Nuclear Information System (INIS)

    Iyer, P.S.; Ganguly, A.K.

    1978-01-01

    Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

  14. The feasibility of 10 keV X-ray as radiation source in total dose response radiation test

    International Nuclear Information System (INIS)

    Li Ruoyu; Li Bin; Luo Hongwei; Shi Qian

    2005-01-01

    The standard radiation source utilized in traditional total dose response radiation test is 60 Co, which is environment-threatening. X-rays, as a new radiation source, has the advantages such as safety, precise control of dose rate, strong intensity, possibility of wafer-level test or even on-line test, which greatly reduce cost for package, test and transportation. This paper discussed the feasibility of X-rays replacing 60 Co as the radiation source, based on the radiation mechanism and the effects of radiation on gate oxide. (authors)

  15. Regulatory control of radiation sources and radioactive materials in Ireland

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fenton, D.; O'Flaherty, T.

    2001-01-01

    The primary legislation governing safety in uses of ionizing radiation in Ireland is the Radiological Protection Act, 1991. This Act provided for the establishment in 1992 of the Radiological Protection Institute of Ireland, and gives the Institute the functions and powers which enable it to be the regulatory body for all matters relating to ionizing radiation. A Ministerial Order made under the Act in 2000 consolidates previous regulations and, in particular, provides for the implementation in Irish law of the 1996 European Union Directive which lays down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionizing radiation. Under the legislation, the custody, use and a number of other activities involving radioactive substances and irradiating apparatus require a licence issued by the Institute. Currently some 1260 licences are in force. Of these, some 850 are in respect of irradiating apparatus only and are issued principally to dentists and veterinary surgeons. The remaining licences involve sealed radiation sources and/or unsealed radioactive substances used in medicine, industry or education. A schedule attached to each licence fully lists the sealed sources to which the licence applies, and also the quantities of radioactive substances which may be acquired or held under the licence. It is an offence to dispose of, or otherwise relinquish possession of, any licensable material other than in accordance with terms and conditions of the licence. Disused sources are returned to the original supplier or, where this is not possible, stored under licence by the licensee who used them. Enforcement of the licensing provisions relies primarily on the programme of inspection of licensees, carried out by the Institute's inspectors. The Institute's Regulatory Service has a complement of four inspectors, one of whom is the Manager of the Service. The Manager reports to one of the Institute's Principal

  16. Locating gamma radiation source by self collimating BGO detector system

    Energy Technology Data Exchange (ETDEWEB)

    Orion, I; Pernick, A; Ilzycer, D; Zafrir, H [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center; Shani, G [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

    1996-12-01

    The need for airborne collimated gamma detector system to estimate the radiation released from a nuclear accident has been established. A BGO detector system has been developed as an array of separate seven cylindrical Bismuth Germanate scintillators, one central detector symmetrically surrounded by six detectors. In such an arrangement, each of the detectors reduced the exposure of other detectors in the array to a radiation incident from a possible specific spatial angle, around file array. This shielding property defined as `self-collimation`, differs the point source response function for each of the detectors. The BGO detector system has a high density and atomic number, and therefore provides efficient self-collimation. Using the response functions of the separate detectors enables locating point sources as well as the direction of a nuclear radioactive plume with satisfactory angular resolution, of about 10 degrees. The detector`s point source response, as function of the source direction, in a horizontal plane, has been predicted by analytical calculation, and was verified by Monte-Carlo simulation using the code EGS4. The detector`s response was tested in a laboratory-scale experiment for several gamma ray energies, and the experimental results validated the theoretical (analytical and Monte-Carlo) results. (authors).

  17. Fabrication of radiation sources for educational purposes from chemical fertilizers using compressing and forming method

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    Chemical fertilizers contain potassium, which is composed of a small amount of naturally occurring potassium-40. The potassium-40 radionuclide emits beta and gamma radiation. Three brands of chemical fertilizer were used to fabricate disk-shaped radiation sources and the fabricated radiation sources were examined for applicability to an educational radiation course. In the examination, tests to determine dependence of count rate on distance, shielding thickness, and shielding materials were conducted using the radiation sources. Results showed that radiation sources fabricated from the three brands of chemical fertilizer were equivalent for explaining radiation characteristics, particularly those related to the dependence of radiation strength on distance and shielding thickness. The relation between shielding effect and mass density can be explained qualitatively. Thus, chemical fertilizer radiation sources can be a useful teaching aid for educational courses to better promote understanding of radiation characteristics and the principles of radiation protection. (author)

  18. Reassessment of the hydrocarbons in Prince William Sound and the Gulf of Alaska : identifying the source using partial least squares

    International Nuclear Information System (INIS)

    Mudge, S.M.

    2001-01-01

    Since the Exxon Valdez oil spill in Prince William Sound, Alaska there has been much discussion regarding the clean-up and long term fate of the oil. There has also been debate regarding the origin of the background hydrocarbons present within Prince William Sound (PWS) and the Gulf of Alaska (GoA). There is evidence that background (pre-spill) hydrocarbons may come from either nearby coal deposits or from natural oil seeps and eroding source rocks in the region. This paper presented a study in which the multivariate statistical methodology of the Partial Least Squares (PLS) was used to reassess the percentage contribution of coal, seep oil, shales and rivers to the hydrocarbon loading in the GoA. Data was provided by researchers at the National Ocean and Atmospheric Administration (NOAA) and the Bowdoin College, for Exxon. The data was analysed using selected sites as sources in order to develop signatures. The signatures were based on 40 and 136 compounds respectively, including the polyaromatic hydrocarbon (PAH) and terpane biomarkers from the Exxon data. The key components describing the sources were fitted to the data for other sites around the GoA to determine the proportion of the variability described by each source. The large complex datasets can be used to develop complex fingerprints for sources rather than using relatively simplistic ratios between selected compounds. The results indicate that 30 per cent of the signature is common between each source and that the small PAHs are the best diagnostic compounds in the model for the oil signature and the large PAHs are good for coal. Naphthalene, methyl and dimethyl naphthalene are the best markers for the seep oil signature. For the pre-spill background, coals and shales are best defined by the larger PAHs such as perylene and benzo(ghi)perylene. In general, the average partitioning between the two sources across all the sampling sites within the region indicated that 53 per cent is attributable to the

  19. Development of a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI)

    International Nuclear Information System (INIS)

    Huang Bormin; Mielikainen, Jarno; Oh, Hyunjong; Allen Huang, Hung-Lung

    2011-01-01

    Satellite-observed radiance is a nonlinear functional of surface properties and atmospheric temperature and absorbing gas profiles as described by the radiative transfer equation (RTE). In the era of hyperspectral sounders with thousands of high-resolution channels, the computation of the radiative transfer model becomes more time-consuming. The radiative transfer model performance in operational numerical weather prediction systems still limits the number of channels we can use in hyperspectral sounders to only a few hundreds. To take the full advantage of such high-resolution infrared observations, a computationally efficient radiative transfer model is needed to facilitate satellite data assimilation. In recent years the programmable commodity graphics processing unit (GPU) has evolved into a highly parallel, multi-threaded, many-core processor with tremendous computational speed and very high memory bandwidth. The radiative transfer model is very suitable for the GPU implementation to take advantage of the hardware's efficiency and parallelism where radiances of many channels can be calculated in parallel in GPUs. In this paper, we develop a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI) launched in 2006 onboard the first European meteorological polar-orbiting satellites, METOP-A. Each IASI spectrum has 8461 spectral channels. The IASI radiative transfer model consists of three modules. The first module for computing the regression predictors takes less than 0.004% of CPU time, while the second module for transmittance computation and the third module for radiance computation take approximately 92.5% and 7.5%, respectively. Our GPU-based IASI radiative transfer model is developed to run on a low-cost personal supercomputer with four GPUs with total 960 compute cores, delivering near 4 TFlops theoretical peak performance. By massively parallelizing the second and third modules, we reached 364x

  20. The concept of recommended working life applied to radiation sources

    International Nuclear Information System (INIS)

    Lorch, E.A.

    1980-01-01

    Consideration is given to the background behind the Radiochemical Centre's decision to introduce values of recommended working life (RWL) of 5, 10 or 15 years for the majority of its radiation sources. Criteria used in assessing RWL included toxicity, half-life and total initial activity of the nuclide, source construction, typical application environments, experience of safety in use and test performance data. The introduction of the concept of RWL has meant that users are becoming aware of the need for regular inspection and assessment of sources, but it is emphasized that the RWL does not constitute a guarantee of performance. It represents an effort by the Radiochemical Centre to ensure the proper use of its products. (U.K.)

  1. Potential GTCC LLW sealed radiation source recycle initiatives

    International Nuclear Information System (INIS)

    Fischer, D.

    1992-04-01

    This report suggests 11 actions that have the potential to facilitate the recycling (reuse or radionuclide) of surplus commercial sealed radiation sources that would otherwise be disposed of as greater-than-Class C low-level radioactive waste. The suggestions serve as a basis for further investigation and discussion between the Department of Energy, Nuclear Regulatory Commission, Agreement States, and the commercial sector. Information is also given that describes sealed sources, how they are used, and problems associated with recycling, including legal concerns. To illustrate the nationwide recycling potential, Appendix A gives the estimated quantity and application information for sealed sources that would qualify for disposal in commercial facilities if not recycle. The report recommends that the Department of Energy initiate the organization of a forum to explore the suggested actions and other recycling possibilities

  2. Characterization of the radiation background at the Spallation Neutron Source

    International Nuclear Information System (INIS)

    DiJulio, Douglas D.; Cherkashyna, Nataliia; Scherzinger, Julius; Khaplanov, Anton; Pfeiffer, Dorothea; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Kanaki, Kalliopi; Kirstein, Oliver; Hall-Wilton, Richard J.; Bentley, Phillip M.; Ehlers, Georg; Gallmeier, Franz X.; Hornbach, Donald E.; Iverson, Erik B.; Newby, Robert J.

    2016-01-01

    We present a survey of the radiation background at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, TN, USA during routine daily operation. A broad range of detectors was used to characterize primarily the neutron and photon fields throughout the facility. These include a WENDI-2 extended range dosimeter, a thermoscientific NRD, an Arktis 4 He detector, and a standard NaI photon detector. The information gathered from the detectors was used to map out the neutron dose rates throughout the facility and also the neutron dose rate and flux profiles of several different beamlines. The survey provides detailed information useful for developing future shielding concepts at spallation neutron sources, such as the European Spallation Source (ESS), currently under construction in Lund, Sweden. (paper)

  3. A general description of the Swedish radiation protection regulations of radioactive sources

    International Nuclear Information System (INIS)

    Staalnacke, C.-G.

    2001-01-01

    The regulation of ionizing radiation in Sweden is based on both the Radiation Protection Act and Ordinance from 1998. The Swedish Radiation Protection Institute (SSI) acts as the regulatory authority for radiation safety and issues detailed regulations in specific areas. The report summarizes how the SSI controls radiation sources, including orphan sources for which a process for analyzing their occurrence has started in Sweden. A number of proposed procedures for the control and follow-up of sealed radioactive sources is provided. (author)

  4. Viking observations at the source region of auroral kilometric radiation

    International Nuclear Information System (INIS)

    Bahnsen, A.; Jespersen, M.; Ungstrup, E.; Pedersen, B.M.; Eliasson, L.; Murphree, J.S.; Elphinstone, R.D.; Blomberg, L.; Holmgren, G.; Zanetti, L.J.

    1989-01-01

    The orbit of the Swedish satellite Viking was optimized for in situ observations of auroral particle acceleration and related phenomena. In a large number of the orbits, auroral kilometric radiation (AKR) was observed, and in approximately 35 orbits the satellite passed through AKR source regions as evidenced by very strong signals at the local electron cyclotron frequency f ce . These sources were found at the poleward edge of the auroral oval at altitudes, from 5,000 to 8,000 km, predominantly in the evening sector. The strong AKR signal has a sharp low-frequency cutoff at or very close to f ce in the source. In addition to AKR, strong broadband electrostatic noise is measured during the source crossings. Energetic (1-15 keV) electrons are always present at and around the AKR sources. Upward directed ion beams of several keV are closely correlated with the source as are strong and variable electric fields, indicating that a region of upward pointing electric field below the observation point is a necessary condition for AKR generation. The plasma density is measured by three independent experiments and it is generally found that the density is low across the whole auroral oval. For some source crossings the three methods agree and show a density depletion (but not always confined to the source region itself), but in many cases the three measurements do not yield consistent results. The magnetic projection of the satellite passes through auroral forms during the source crossings, and the strongest AKR events seem to be connected with kinks in an arc or more complicated structures

  5. An inverse source location algorithm for radiation portal monitor applications

    International Nuclear Information System (INIS)

    Miller, Karen A.; Charlton, William S.

    2010-01-01

    Radiation portal monitors are being deployed at border crossings throughout the world to prevent the smuggling of nuclear and radiological materials; however, a tension exists between security and the free-flow of commerce. Delays at ports-of-entry have major economic implications, so it is imperative to minimize portal monitor screening time. We have developed an algorithm to locate a radioactive source using a distributed array of detectors, specifically for use at border crossings. To locate the source, we formulated an optimization problem where the objective function describes the least-squares difference between the actual and predicted detector measurements. The predicted measurements are calculated by solving the 3-D deterministic neutron transport equation given an estimated source position. The source position is updated using the steepest descent method, where the gradient of the objective function with respect to the source position is calculated using adjoint transport calculations. If the objective function is smaller than the convergence criterion, then the source position has been identified. This paper presents the derivation of the underlying equations in the algorithm as well as several computational test cases used to characterize its accuracy.

  6. Photoacoustic Sounds from Meteors.

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, Richard E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tencer, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sweatt, William C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hogan, Roy E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Spurny, Pavel [Academy of Sciences of the Czech Republic (ASCR), Prague (Czech Republic)

    2015-03-01

    High-speed photometric observations of meteor fireballs have shown that they often produce high-amplitude light oscillations with frequency components in the kHz range, and in some cases exhibit strong millisecond flares. We built a light source with similar characteristics and illuminated various materials in the laboratory, generating audible sounds. Models suggest that light oscillations and pulses can radiatively heat dielectric materials, which in turn conductively heats the surrounding air on millisecond timescales. The sound waves can be heard if the illuminated material is sufficiently close to the observer’s ears. The mechanism described herein may explain many reports of meteors that appear to be audible while they are concurrently visible in the sky and too far away for sound to have propagated to the observer. This photoacoustic (PA) explanation provides an alternative to electrophonic (EP) sounds hypothesized to arise from electromagnetic coupling of plasma oscillation in the meteor wake to natural antennas in the vicinity of an observer.

  7. Safety issues in the handling of radiation sources in category IV gamma radiation facilities

    International Nuclear Information System (INIS)

    Kohli, A.K.

    2002-01-01

    There is potential for incidents/accidents related to handling of radiation sources. This is increasing due to the fact that more number of plants that too with much larger levels of activity are now coming up. Such facilities produce very high levels of exposure rates during irradiation. A person accidentally present in the irradiation cell can receive a lethal dose within a very short time. Apart from safety requirements during operation and maintenance of these facilities, safety during loading and unloading of sources is important. Category IV type irradiators are the most common. Doubly encapsulated Co-60 slugs are employed to form the source pencils. These irradiators employ a water pool for safely storing the source pencils when irradiation of the products is not going on or when human access is needed into the irradiation cell for some maintenance or source loading/unloading operations. Safety during loading/unloading operations of source pencils is important. In design itself care needs to be taken such that all such operations are convenient and any incident will not lead to a situation where it becomes difficult to come out. Different situations, which can arise during handling of radiation sources and suggested designs to obviate such tight situations, are discussed. (Author)

  8. Risk perception in the process of working with radiation sources

    International Nuclear Information System (INIS)

    Carneiro, J.C.G.; Levy, D.; Sanches, M.P.; Rodrigues, D.L.; Sordi, G.M.A.A.

    2017-01-01

    This study discusses occupational risk under three distinct aspects, which are often interconnected or interdependent in the work environment. These are: environmental risks, human failures and equipment failures. The article addresses the potential exposure in the workplace, caused by the agent's physical radiation risk, resulting from handling with sources of ionizing radiation. Based on the history of accidents occurring in normal operations, the study summarizes the main accidents in various facilities and possible causes involving the three aspects of risk. In its final considerations, it presents the lessons learned and the measures to be taken with the intention of contributing to the prevention and mitigation of risks in the work environment. The analysis of accident cases and their causes provide valuable information to prevent the risk of similar accidents and contribute to the improvement of operational projects and procedures

  9. National system of notification, authorization and inspection for the control of radiation sources in Ghana

    International Nuclear Information System (INIS)

    Schandorf, C.; Darko, E.O.; Yeboah, J.; Asiamah, S.D.

    2001-01-01

    The Radiation Protection Board (RPB) was established in 1993 in Ghana as the regulatory authority for radiation protection and safety of radiation sources; its functions are prescribed in the 1993 national radiation protection regulation. The report describes how the country's radiation protection and safety infrastructure have been established, including the RPB's organizational structure, with reference in particular to the main activities carried out by both the Regulatory Control Department and the Radiation and Waste Safety Department. It also briefly mentions the existing RPB human resources; the national system of notification, authorization and inspection of radiation sources; the inventory of radiation sources; and the management of disused radiation sources. Finally, the report identifies the two main problem areas regarding the regulatory control of radiation sources in the country. (author)

  10. Recent equivalent source methods for quantifying airborne and structureborne sound transfer

    NARCIS (Netherlands)

    Verheij, J.W.

    1992-01-01

    Characteristically noise reduction in technical products like road vehicles, ships, aircraft and machines is complicated by the multitude of primary sources and transfer paths. Examples of well-known approaches for transfer path investigations are selective shielding, mechanical uncoupling,

  11. Production of iridium-192 radiation sources: Indian Experience

    International Nuclear Information System (INIS)

    Sastry, K.V.S.; Kolhe, O.T.; Nagarja, P.S.; Paramr, Y.D.

    2002-01-01

    Board of Radiation and Isotope Technology (BRIT), a unit under the Department of Atomic Energy is fabricating and supplying Ir-192 industrial radiography sources for various models of radiography cameras for use in the industry for non-destructive testing. Basically these sources are fabricated by encapsulating the required quantity of the activity in stainless steel 316 L capsules using Tungsten Inert gas welding process and crimping/attaching to the respective pigtail assemblies of the radiography cameras. The inactive iridium pellets are irradiated in the DHRUVA reactor at a flux on 1.8 X 10 14 n/cm 2 /sec. The performance classification of these source encapsulation for various conditions of normal and accidental nature are tested by subjecting the prototype sources as per the standard laid down by the regulatory authority, Atomic Energy Regulatory Board, in India. The sources are fabricated as per the national and international standards. Activity of the sources varies from 37O GBq (10 Ci ) to 2.96 TBq (80 Ci ) source strength depending on the requirement of the user. The specific activity of the Ir-192 sources supplied is around 7.4 TBq/gm (200 Ci/gm ). Quality control /Assurance for the manufacture of the source begins from the procurement of the raw material and ends with the finished source. Ir- 192 in the form of -0.3 mm diameter (0.1 mm dia wire of Ir-25 % and Pt-75% sheathed in pure platinum of 0.1 mm thick) is being supplied for use in the treatment of cancer of cervix, tongue etc. by brachytherapy. This is supplied in lengths of 50 cm / 100 cm with 37 - 185 GBq/cm ( 1-5 mCi/cm) activity. Annually 925 TBq (25 kCi) of Ir-192 for industrial radiography and about 60 meters of wire for brachytherapy are being fabricated and supplied. Because of the quality of these sources BRIT not only caters to the Indian industry but also is able to export sources to the third world countries. (Author)

  12. The competent person in radiation protection: practical radiation protection for industry and research - unsealed sources

    International Nuclear Information System (INIS)

    Bruchet, H.

    2009-01-01

    The mission of the competent person in radiation protection has been broadly developed these last years to take an essential function in firm:study of working place, delimitation of regulated areas, monitoring of exposure, relations with authorities. The competent person in radiation protection must follow a training, defined by decree and shared in two parts: a theoretical part used as compulsory subjects and a practical part specific to the different sectors of activity (research, industry, medical centers, nuclear facilities) as well as the radiation use type. This volume corresponds to the practical module devoted to the industrial and research facilities concerned by the possession of management of sealed or unsealed sources. In accordance with the regulations stipulating that this module must allow to apply the theoretical knowledge to concrete situations in work. It includes eight chapters as following: radiation protection in industrial and research facilities, use of sources and associated risks, fitting out professional premises, evaluation of exposure, control of radiation protection; use of detection equipment and radioactive contamination and exposure measurement equipment, associated to methods and calculation tools; radioactive waste management; accidental or damaged situations management; methodology of working place analysis completed by the application to practical cases found in laboratories. (N.C.)

  13. Measurement of radiation skyshine with D-T neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, S.; Nishitani, T. E-mail: nisitani@naka.jaeri.go.jp; Ochiai, K.; Kaneko, J.; Hori, J.; Sato, S.; Yamauchi, M.; Tanaka, R.; Nakao, M.; Wada, M.; Wakisaka, M.; Murata, I.; Kutsukake, C.; Tanaka, S.; Sawamura, T.; Takahashi, A

    2003-09-01

    The D-T neutron skyshine experiments have been carried out at the Fusion Neutronics Source (FNS) of JAERI with the neutron yield of {approx}1.7x10{sup 11} n/s. The concrete thickness of the roof and the wall of a FNS target room are 1.15 and 2 m, respectively. The FNS skyshine port with a size of 0.9x0.9 m{sup 2} was open during the experimental period. The radiation dose rate outside the target room was measured a maximum distance of 550 m from the D-T target point with a spherical rem-counter. Secondary gamma-rays were measured with high purity Ge detectors and NaI scintillation counters. The highest neutron dose was about 9x10{sup -22} Sv/(source neutron) at a distance of 30 m from the D-T target point and the dose rate was attenuated to 4x10{sup -24} Sv/(source neutron) at a distance of 550 m. The measured neutron dose distribution was analyzed with Monte Carlo code MCNP-4B and a simple line source model. The MCNP calculation overestimates the neutron dose in the distance range larger than 230 m. The line source model agrees well with the experimental results within the distance of 350 m.

  14. Freeze drying method for preparing radiation source material

    International Nuclear Information System (INIS)

    Mosley, W.C. Jr.; Smith, P.K.

    1975-01-01

    A solution containing radioisotope and palladium values is atomized into an air flow entering a cryogenically cooled chamber where the solution is deposited on the chamber walls as a thin layer of frozen material. The solvent portion of the frozen material is sublimated into a cold trap by elevating the temperature within the chamber while withdrawing solvent vapors. The residual crystals are heated to provide a uniformly mixed powder of palladium metal and a refractory radioisotope compound. The powder is thereafter consolidated into a pellet and further shaped into rod, wire or sheet form for easy apportionment into individual radiation sources. (U.S.)

  15. Research Activities Using Indus-1 Synchrotron Radiation Source

    International Nuclear Information System (INIS)

    Lodha, G. S.; Deb, S. K.

    2010-01-01

    Indus-1 is an efficient SR source in the soft x-ray / vacuum ultra violet region of the electromagnetic spectrum. For Indus-1, the higher order energy contamination in soft x-ray region, heat load and radiation safety problems are also significantly low. At present, soft x-ray-VUV reflectivity, angle integrated and angle resolved photo electron spectroscopy (ARPES), photo physics and high resolution vacuum ultra violet spectroscopy, beamlines are operational. The paper presents some of the recent studies carried out using In-dus-1.

  16. Search begins for missing radiation sources in Republic of Georgia

    International Nuclear Information System (INIS)

    2002-01-01

    An international team assembled by the IAEA will begin a search today for two abandoned Strontium 90 generators in a ca. 550 sq. km area of Western Georgia. About 80 people will take part in the two-week search beginning on Monday, 10 June. Radiation experts for the IAEA, India, France, Turkey and the U.S. are also part of the team, which will set out on horseback, foot and by car. The second phase - an aerial and road survey covering different territory - is scheduled to begin in early September. The objective is to locate and recover other known or suspected orphaned radioactive sources in the country

  17. Active sound reduction system and method

    NARCIS (Netherlands)

    2016-01-01

    The present invention refers to an active sound reduction system and method for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being. This system comprises a primary sound source, at least one speaker as a secondary sound

  18. Radiation protection data sheet. Radiation protection data sheets for the use of radionuclides in unsealed sources

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    These radiation protection data sheet are devoted to responsible persons and employees of various laboratories or medical, pharmaceutical, university and industrial departments where radionuclides are handled as well as all the persons who attend to satisfy in this field. They contain the essential radiation protection data for the use of unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography. This new series includes the following radionuclides: californium 252, curium 244, gallium 67, indium 113m, plutonium 238, plutonium 239, polonium 210, potassium 42, radium 226, thorium 232, uranium 238 and zinc 65. (O.M.)

  19. Radiation protection for the illegal governmental use of radiation sources. A case study

    International Nuclear Information System (INIS)

    Becker, K.

    2000-01-01

    Probably for the first time, illegal governmental uses of radiation sources, including the administrative infrastructure such as special radiation protection regulation, an advisory body etc., have been documented by the evaluation of the documents of the Ministry of State Security in the former German Democratic Republic (East Germany). Over a thousand persons, but also documents, money bills etc. were marked with a wide variety of radionuclides and traced with specially developed detectors. Among the many different nuclides provided regularly from the Rossendorf Research Center near Dresden, in particular 46 Sc was popular. (orig.) [de

  20. The adaptive collision source method for discrete ordinates radiation transport

    International Nuclear Information System (INIS)

    Walters, William J.; Haghighat, Alireza

    2017-01-01

    Highlights: • A new adaptive quadrature method to solve the discrete ordinates transport equation. • The adaptive collision source (ACS) method splits the flux into n’th collided components. • Uncollided flux requires high quadrature; this is lowered with number of collisions. • ACS automatically applies appropriate quadrature order each collided component. • The adaptive quadrature is 1.5–4 times more efficient than uniform quadrature. - Abstract: A novel collision source method has been developed to solve the Linear Boltzmann Equation (LBE) more efficiently by adaptation of the angular quadrature order. The angular adaptation method is unique in that the flux from each scattering source iteration is obtained, with potentially a different quadrature order used for each. Traditionally, the flux from every iteration is combined, with the same quadrature applied to the combined flux. Since the scattering process tends to distribute the radiation more evenly over angles (i.e., make it more isotropic), the quadrature requirements generally decrease with each iteration. This method allows for an optimal use of processing power, by using a high order quadrature for the first iterations that need it, before shifting to lower order quadratures for the remaining iterations. This is essentially an extension of the first collision source method, and is referred to as the adaptive collision source (ACS) method. The ACS methodology has been implemented in the 3-D, parallel, multigroup discrete ordinates code TITAN. This code was tested on a several simple and complex fixed-source problems. The ACS implementation in TITAN has shown a reduction in computation time by a factor of 1.5–4 on the fixed-source test problems, for the same desired level of accuracy, as compared to the standard TITAN code.

  1. Categorization of radioactive sources. Revision of IAEA-TECDOC-1191, Categorization of radiation sources

    International Nuclear Information System (INIS)

    2003-07-01

    Radioactive sources are used throughout the world for a wide variety of peaceful purposes in industry, medicine, agriculture, research and education; and they are also used in military applications. The International Basic Safety Standards provide an internationally harmonized basis for ensuring the safe and secure use of sources of ionizing radiation. Because of the wide variety of uses and activities of radiation sources, a categorization system is necessary so that the controls that are applied to the sources are commensurate with the radiological risks. In September 1998, following an assessment of the major findings of the first International Conference on the Safety of Radiation Sources and the Security of Radioactive Materials, held in Dijon, France, from 14 to 18 September 1998 (the Dijon Conference), the IAEA's General Conference (in resolution GC(42)/RES/12), inter alia, encouraged all governments 'to take steps to ensure the existence within their territories of effective national systems of control for ensuring the safety of radiation sources and the security of radioactive materials' and requested the Secretariat 'to prepare for the consideration of the Board of Governors a report on: (i) how national systems for ensuring the safety of radiation sources and the security of radioactive materials can be operated at a high level of effectiveness; and, (ii) whether international undertakings concerned with the effective operation of such systems and attracting broad adherence could be formulated'. In February 1999, the Secretariat submitted to the IAEA Board of Governors a report prepared in response to the request made of it by the General Conference. The Board took up the report at its March 1999 session and, inter alia, requested the Secretariat to prepare an action plan that took into account the conclusions and recommendations in the report, and the Board's discussion of the report. In August 1999, the Secretariat circulated a proposed Action Plan for

  2. Sources of gamma radiation in a reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Matts

    1959-05-15

    In a thermal reactor the gamma ray sources of importance for shielding calculations and related aspects are 1) fission, 2) decay of fission products, 3) capture processes in fuel, poison and other materials, 4) inelastic scattering in the fuel and 5) decay of capture products. The energy release and the gamma ray spectra of these sources have been compiled or estimated from the latest information available, and the results are presented in a general way to permit application to any thermal reactor, fueled with a mixture of {sup 235}U and {sup 238}U. As an example the total spectrum and the spectrum of radiation escaping from a fuel rod in the Swedish R3-reactor are presented.

  3. Production of radioisotopic gamma radiation sources in JAERI

    International Nuclear Information System (INIS)

    Katoh, Hisashi; Kogure, Hiroto; Suzuki, Kyohei

    1980-04-01

    The present state of production of gamma radiation sources in Japan Atomic Energy Research Institute (JAERI) is described. Sources of 192 Ir, 60 Co and 170 Tm for industrial and 198 Au and 192 Ir for medical applications are produced and delivered routinely by JAERI. Prefabricated assembly targets are irradiated in JRR-2, JRR-3, JRR-4 or JMTR. The irradiated targets are disassembled in a heavy density concrete cave or a lead-shielded cell, depending on the level of radioactivity. The yield of radioactivity in each target is measured with the aid of an ionization chamber. Where necessary, irradiated targets are encapsulated hermetically in capsules of aluminium, stainless steel or other material. The yield of radioactivity is estimated in relation with the burn-up of target nuclide and product nuclide. (author)

  4. Heat Transfer by Thermo-Capillary Convection. Sounding Rocket COMPERE Experiment SOURCE

    Science.gov (United States)

    Fuhrmann, Eckart; Dreyer, Michael

    2009-08-01

    This paper describes the results of a sounding rocket experiment which was partly dedicated to study the heat transfer from a hot wall to a cold liquid with a free surface. Natural or buoyancy-driven convection does not occur in the compensated gravity environment of a ballistic phase. Thermo-capillary convection driven by a temperature gradient along the free surface always occurs if a non-condensable gas is present. This convection increases the heat transfer compared to a pure conductive case. Heat transfer correlations are needed to predict temperature distributions in the tanks of cryogenic upper stages. Future upper stages of the European Ariane V rocket have mission scenarios with multiple ballistic phases. The aims of this paper and of the COMPERE group (French-German research group on propellant behavior in rocket tanks) in general are to provide basic knowledge, correlations and computer models to predict the thermo-fluid behavior of cryogenic propellants for future mission scenarios. Temperature and surface location data from the flight have been compared with numerical calculations to get the heat flux from the wall to the liquid. Since the heat flux measurements along the walls of the transparent test cell were not possible, the analysis of the heat transfer coefficient relies therefore on the numerical modeling which was validated with the flight data. The coincidence between experiment and simulation is fairly good and allows presenting the data in form of a Nusselt number which depends on a characteristic Reynolds number and the Prandtl number. The results are useful for further benchmarking of Computational Fluid Dynamics (CFD) codes such as FLOW-3D and FLUENT, and for the design of future upper stage propellant tanks.

  5. Regulatory Control of Radiation Sources. Safety Guide (Arabic Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  6. Probable sources of errors in radiation therapy (abstract)

    International Nuclear Information System (INIS)

    Khan, U.H.

    1998-01-01

    It is fact that some errors are always in dose-volume prescription, management of radiation beam, derivation of exposure, planning the treatment and finally the treatment of the patient ( a three dimensional subject). This paper highlights all the sources of error and relevant methods to decrease or eliminate them, thus improving the over-all therapeutic efficiency and accuracy. It is a comprehensive teamwork of the radiotherapist, medical radiation physicist, medical technologist and the patient. All the links, in the whole chain of radiotherapy, are equally important and duly considered in the paper. The decision for Palliative or Radical treatment is based on the nature and extent disease, site, stage, grade, length of the history of condition and biopsy reports etc. This may entail certain uncertainties in Volume of tumor, quality and quantity of radiation and dose fractionation etc, which may be under or over-estimated. An effort has been made to guide the radiotherapist in avoiding the pitfalls in the arena of radiotherapy. (author)

  7. Application of PSA techniques to synchrotron radiation source facilities

    International Nuclear Information System (INIS)

    Sanyasi Rao, V.V.S.; Vinod, G.; Vaze, K.K.; Sarkar, P.K.

    2011-01-01

    Synchrotron radiation sources are increasingly being used in research and medical applications. Various instances of overexposure in these facilities have been reported in literature. These instances have lead to the investigation of the risks associated with them with a view to minimise the risks and thereby increasing the level of safety. In nuclear industry, Probabilistic Safety Assessment (PSA) methods are widely used to assess the risk from nuclear power plants. PSA presents a systematic methodology to evaluate the likelihood of various accident scenarios and their possible consequences using fault/event tree techniques. It is proposed to extend similar approach to analyse the risk associated with synchrotron radiation sources. First step for such an analysis is establishing the failure criteria, considering the regulatory stipulations on acceptable limits of dose due to ionization radiation from normal as well as beam loss scenarios. Some possible scenarios considered in this study are (1) excessive Bremsstrahlung in the ring due to loss of vacuum, (2) Target failure due to excessively focused beam (3) mis-directed/mis-steered beam (4) beam loss and sky shine. Hazard analysis needs to cover the beam transfer line, storage ring and experimental beam line areas. Various safety provisions are in place to minimize the hazards from these facilities such as access control interlock systems, radiation shielding for storage ring and beam lines and safety shutters (for beam lines). Experimental beam line area is the most vulnerable locations that need to be critically analysed. There are multiple beam lines, that have different safety provisions and consequences from postulated beam strikes will also be different and this increases the complexity of analysis. Similar studies conducted for such experimental facilities have identified that the radiation safety interlock system, used to control access to areas inside ring and the hutches of beamline facilities has an

  8. Borehole disposal of spent radiation sources: 1. Principles

    International Nuclear Information System (INIS)

    Blerk, J.J. van; Kozak, M.W.

    2000-01-01

    Large numbers of spent radiation sources from the medical and other technical professions exist in many countries, even countries that do not possess facilities related to the nuclear fuel cycle, that have to be disposed. This is particularly the case in Africa, South America and some members of the Russian Federation. Since these sources need to be handled separately from the other types of radioactive waste, mainly because of their activity to volume ratio, countries (even those with access to operational repositories) find it difficult to manage and dispose this waste. This has led to the use of boreholes as disposal units for these spent sources by some members of the Russian Federation and in South Africa. However, the relatively shallow boreholes used by these countries are not suitable for the disposal of isotopes with long half-lifes, such as 226 Ra and 241 Am. With this in mind the Atomic Energy Corporation of South Africa initiated the development of the BOSS disposal concept - an acronym for Borehole disposal Of Spent Sources - as part of an International Atomic Energy Agency (IAEA) AFRA I-14 Technical Corporation (TC) project. In this paper, the principles of this disposal concept, which is still under development, will be discussed. (author)

  9. Insurance of Radioisotopes and Ionizing Radiation Sources in France

    International Nuclear Information System (INIS)

    Stanislas, A.

    2008-01-01

    Since the early sixties, Assuratome has amassed quite a long experience in the insurance of radioisotopes and more generally of ionising radiation sources when they are used transported or stored outside a nuclear installation. Aware of the specific dangers of such devices, and having no experience in this domain French insurers were looking for a pragmatic solution which would permit to continue to provide cover for users or fabricants of small radioactive sources and in the meantime to keep a rigorous control on the claims and on the loss ratio which would be achieved over the years. Hence the decision was taken by the French Insurance market to entrust the French Nuclear Insurance Pool, Assuratome, as the recommended body for delivering specific 'nuclear policies' as an expert for this category of business. The next step was to make sure that the 'conventional policies' would not provide the same cover. Therefore, an appropriate exclusion clause was introduced in all the general conditions of the TPL Policies of the conventional market and consequently in the majority, if not all, the reinsurance treaties. Besides the obvious advantage resulting in the management of this category of business in a centralised body, a major benefit of this situation is based on the strict control by the insurer of the compulsory authorisation delivered by the authorities to the owner of the radioactive source. Unofficial sources having in principal no insurance possibilities in France their use would be virtually impossible.(author)

  10. Building competence in radiation protection and the safe use of radiation sources. Safety guide (Spanish ed.)

    International Nuclear Information System (INIS)

    2010-01-01

    This Safety Guide makes recommendations concerning the building of competence in protection and safety within a national radiation protection infrastructure and provides guidance for setting up the structure for a national strategy. It relates to the training and assessment of qualification of new personnel and the retraining of existing personnel in order to develop and maintain appropriate levels of competence. It provides the necessary guidance to meet the requirements laid down in Safety Series No. 115, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. Contents: 1. Introduction; 2. Responsibilities for building competence in protection and safety; 3. Education, training and work experience; 4. A national strategy for building competence in protection and safety.

  11. Building competence in radiation protection and the safe use of radiation sources. Safety guide (Arabic ed.)

    International Nuclear Information System (INIS)

    2006-01-01

    This Safety Guide makes recommendations concerning the building of competence in protection and safety within a national radiation protection infrastructure and provides guidance for setting up the structure for a national strategy. It relates to the training and assessment of qualification of new personnel and the retraining of existing personnel in order to develop and maintain appropriate levels of competence. It provides the necessary guidance to meet the requirements laid down in Safety Series No. 115, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. Contents: 1. Introduction; 2. Responsibilities for building competence in protection and safety; 3. Education, training and work experience; 4. A national strategy for building competence in protection and safety.

  12. Data survey about radiation protection and safety of radiation sources in research laboratories

    International Nuclear Information System (INIS)

    Paura, Clayton L.; Dantas, Ana Leticia A.; Dantas, Bernardo M.

    2005-01-01

    In Brazil, different types of research using unsealed sources are developed with a variety of radioisotopes. In such activities, professionals and students involved are potentially exposed to internal contamination by 14 C, 45 Ca, 51 Cr, 3 H, 125 I, 32 P, 33 P, 35 S, 90 Sr and 99m Tc. The general objective of this work is to evaluate radiological risks associated to these practices in order to supply information for planning actions aimed to improve radiation protection conditions in research laboratories. The criteria for risk evaluation and the safety aspects adopted in this work were based on CNEN Regulation 6.02 and in IAEA and NRPB publications. The survey of data was carried out during visits to laboratories in public Universities located in the city of Rio de Janeiro where unsealed radioactive sources are used in biochemistry, biophysics and genetic studies. According to the criteria adopted in this work, some practices developed in the laboratories require evaluation of risk of internal contamination depending on the conditions of source manipulation. It was verified the need for training of users of radioactive materials in this type of laboratory. This can be facilitated by the use of basic guides for the classification of areas, radiation protection, safety and source security in research laboratories. It was also observed the need for optimization of such practices in order to minimize the contact with sources. It is recommended to implement more effective source and access controls as a way to reduce risks of individual radiation exposure and loss of radioactive materials (author)

  13. Methods of computer experiment in gamma-radiation technologies using new radiation sources

    CERN Document Server

    Bratchenko, M I; Rozhkov, V V

    2001-01-01

    Presented id the methodology of computer modeling application for physical substantiation of new irradiation technologies and irradiators design work flow. Modeling tasks for irradiation technologies are structured along with computerized methods of their solution and appropriate types of software. Comparative analysis of available packages for Monte-Carlo modeling of electromagnetic processes in media is done concerning their application to irradiation technologies problems. The results of codes approbation and preliminary data on gamma-radiation absorbed dose distributions for nuclides of conventional sources and prospective Europium-based gamma-sources are presented.

  14. The IAEA Regional Training Course on Regulatory Control of Radiation Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Materials of the IAEA Regional Training Course contains 8 presented lectures. Authors deals with regulatory control of radiation sources. The next materials of the IAEA were presented: Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. (IAEA-TECDOC-1067); Safety assessment plants for authorization and inspection of radiation sources (IAEA-TECDOC-1113); Regulatory authority information system RAIS, Version 2.0, Instruction manual

  15. The actuality and discussion for the data management of radiation sources

    International Nuclear Information System (INIS)

    Yang Yaoyun; Huang Chaoyun; Wang Xiaofeng; Chen Dongliang; Fu Jie

    2008-01-01

    Large amounts of data and information in radiation safety license permits, supervision and inspection have been accumulated in China. Data management of radiation sources is an important aspect of radiation sources security. This paper introduces the main elements, tache and actuality of data management, the strengths and weaknesses of RAIS system in use. This paper analyzes and discusses the approach of establishing radiation sources monitoring information system network. (authors)

  16. Numerical study of the aerodynamics of sound sources in a bass-reflex port

    Directory of Open Access Journals (Sweden)

    V.M. Garcia-Alcaide

    2017-01-01

    Full Text Available The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.

  17. TEMPORAL AND SPATIAL VARIATION IN SOLAR RADIATION AND PHOTO-ENHANCED TOXICITY RISKS OF SPILLED OIL IN PRINCE WILLIAM SOUND, ALASKA

    Science.gov (United States)

    Solar irradiance (W/m2) and downwelling diffuse attenuation coefficients (Kd; m-1) were determined in several locations in Prince William Sound, Alaska, USA, between April 2003 and December 2005 to assess temporal and spatial variation in solar radiation and the risks of photoenh...

  18. Technique for estimating the sound power level radiated by pneumatic rock drills and the evaluation of a CSIR prototype rock drill with engineering noise controls

    CSIR Research Space (South Africa)

    Kovalchik, PG

    2009-05-01

    Full Text Available and the radiation patterns in octave and 1/3 octave bands. Overall sound power level is also determined. This paper also reports the results obtained by using this procedure to evaluate a SECO S215 standard production drill and a CSIR Miningtek prototype rock drill...

  19. Sound radiation contrast in MR phase images. Method for the representation of elasticity, sound damping, and sound impedance changes; Schallstrahlungskontrast in MR-Phasenbildern. Methode zur Darstellung von Elastizitaets-, Schalldaempfungs- und Schallimpedanzaenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Radicke, Marcus

    2009-12-18

    The method presented in this thesis combines ultrasound techniques with the magnetic-resonance tomography (MRT). An ultrasonic wave generates in absorbing media a static force in sound-propagation direction. The force leads at sound intensities of some W/cm{sup 2} and a sound frequency in the lower MHz range to a tissue shift in the micrometer range. This tissue shift depends on the sound power, the sound frequency, the sound absorption, and the elastic properties of the tissue. A MRT sequence of the Siemens Healthcare AG was modified so that it measures (indirectly) the tissue shift, codes as grey values, and presents as 2D picture. By means of the grey values the sound-beam slope in the tissue can be visualized, and so additionally sound obstacles (changes of the sound impedance) can be detected. By the MRT images token up spatial changes of the tissue parameters sound absorption and elasticity can be detected. In this thesis measurements are presented, which show the feasibility and future chances of this method especially for the mammary-cancer diagnostics. [German] Die in dieser Arbeit praesentierte Methode kombiniert Ultraschalltechniken mit der Magnetresonanztomographie (MRT). Eine Ultraschallwelle ruft in absorbierenden Medien eine statische Kraft in Schallausbreitungsrichtung hervor. Die Kraft fuehrt bei Schallintensitaeten von einigen W/cm{sup 2} und einer Schallfrequenz im niederen MHz-Bereich zu einer Gewebeverschiebung im Mikrometerbereich. Diese Gewebeverschiebung haengt ab von der Schallleistung, der Schallfrequenz, der Schallabsorption und den elastischen Eigenschaften des Gewebes. Es wurde eine MRT-Sequenz der Siemens Healthcare AG modifiziert, so dass sie (indirekt) die Gewebeverschiebung misst, als Grauwerte kodiert und als 2D-Bild darstellt. Anhand der Grauwerte kann der Schallstrahlverlauf in dem Gewebe visualisiert werden, und so koennen zusaetzlich Schallhindernisse (Aenderungen der Schallkennimpedanz) aufgespuert werden. Mit den

  20. Notification and authorization for the use of radiation sources (Supplement to IAEA Safety Standards Series No. GS-G-1.5)

    International Nuclear Information System (INIS)

    2011-10-01

    The achievement and maintenance of a high level of safety in the use of radiation sources depend on there being a sound legal and governmental infrastructure, including a national regulatory body with well-defined responsibilities and functions. These responsibilities and functions include establishing and implementing a system for notification and authorization for control over radiation sources, including a system for review and assessment of applications for authorization. The Safety Requirements publication entitled Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety establishes the requirements for legal and governmental infrastructure. The term 'infrastructure' refers to the underlying structure of systems and organizations. This includes requirements concerning the establishment of a regulatory body for radiation sources and the responsibilities and functions assigned to it. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or the BSS) establish basic requirements for protection against risks associated with exposure to ionizing radiation and for the safety of radiation sources. The application of the BSS is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities to for radiation protection and safety. This TECDOC provides practical guidance on the process for dealing with applications for authorization and accepting notifications to regulatory bodies. Examples of guidelines that may be used by persons required to notify or apply for authorization and of the regulatory body's review and assessment procedures are provided in the Appendices. The TECDOC is oriented towards national regulatory infrastructures concerned with protection and safety for radiation sources used in medicine, industry, agriculture, research and education. The IAEA

  1. Flux and brightness calculations for various synchrotron radiation sources

    International Nuclear Information System (INIS)

    Weber, J.M.; Hulbert, S.L.

    1991-11-01

    Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring

  2. Active Control of Radiated Sound With Integrated Piezoelectric Composite Structures. Volume 3 Appendices (Concl.)

    National Research Council Canada - National Science Library

    Fuller, Christopher

    1998-01-01

    ... covered with an acoustic diaphragm configured in a flextensional type manner. The resultant PANEL source after many iterations of analysis, development, construction and testing was found to provide amplification ratios of around 250...

  3. Active Control of Radiated Sound with Integrated Piezoelectric Composite Structures. Volume 1

    National Research Council Canada - National Science Library

    Fuller, Christopher

    1998-01-01

    ... covered with an acoustic diaphragm configured in a flextensional type manner. The resultant PANEL source after many iterations of analysis, development, construction and testing was found to provide amplification ratios of around 250...

  4. Active Control of Radiated Sound With Integrated Piezoelectric Composite Structures. Volume 3: Appendices (Concl.)

    National Research Council Canada - National Science Library

    Fuller, Christopher

    1998-01-01

    ... covered with an acoustic diaphragm configured in a flextensional type manner. The resultant PANEL source after many iterations of analysis, development, construction and testing was found to provide amplification ratios of around 250...

  5. Global source attribution of sulfate aerosol and its radiative forcing

    Science.gov (United States)

    Yang, Y.; Wang, H.; Smith, S.; Easter, R. C.; Ma, P. L.; Qian, Y.; Li, C.; Yu, H.; Rasch, P. J.

    2017-12-01

    Sulfate is an important aerosol that poses health risks and influences climate. Due to long-range atmospheric transport, local sulfate pollution could result from intercontinental influences, making domestic efforts of improving air quality inefficient. Accurate understanding of source attribution of sulfate and its radiative forcing is important for both regional air quality improvement and global climate mitigation. In this study, for the first time, a sulfur source-tagging capability is implemented in the Community Atmosphere Model (CAM5) to quantify the global source-receptor relationships of sulfate and its direct and indirect radiative forcing (DRF and IRF). Near-surface sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate is primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 20% of sulfate concentrations over North Africa, Russia and Central Asia. Sources from the Middle East account for 20% of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 20% over South Asia in spring. East Asia accounts for about 50% of sulfate over Southeast Asia in winter and autumn, 15% over Russia in summer, and 10% over North America in spring. South Asia contributes to 25% of sulfate over Southeast Asia in spring. Lifetime of aerosols, together with regional export, is found to determine regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with 75% contributed by anthropogenic sulfate and 25% contributed by natural sulfate. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes the most to the total DRF. East Asia has the largest contribution of 20-30% over the Northern Hemisphere mid- and high-latitudes. A 20% perturbation of sulfate and its precursor emissions gives a sulfate IRF of -0.44 W m-2. DMS has the

  6. Immediate Dose Assessment for Radiation Accident in Laboratory Containing Gamma Source and/or Neutron Source

    International Nuclear Information System (INIS)

    Ahmed, E.M.

    2012-01-01

    One of the most important safety requirements for any place containing radiation sources is an accurate and fast way to assess the dose rate in both normal and accidental case. In normal case, the source is completely protected inside its surrounded shields in case of non use. In some cases this source may stuck outside its shield. In this case the walls of the place act as a shield. Many studies were carried for obtaining the most appropriate materials that may be used as shielding depending on their efficiency and also their cost. As concrete- with different densities- is the most available constructive material, this study presented a theoretical model using MCNP-4B code, based on Monte Carlo method to estimate the dose rate distribution in a laboratory with concrete walls in case of source stuck accident. The study dealt with Cs-137 as gamma source and Am-Be-241 as neutron source. Two different densities of concrete and also different thicknesses of walls were studied. The used model was verified by comparing the results with a practical study concerning with the effect of adding carbon powder to the concrete. The results showed good agreement

  7. Direct Computation of Sound Radiation by Jet Flow Using Large-scale Equations

    Science.gov (United States)

    Mankbadi, R. R.; Shih, S. H.; Hixon, D. R.; Povinelli, L. A.

    1995-01-01

    Jet noise is directly predicted using large-scale equations. The computational domain is extended in order to directly capture the radiated field. As in conventional large-eddy-simulations, the effect of the unresolved scales on the resolved ones is accounted for. Special attention is given to boundary treatment to avoid spurious modes that can render the computed fluctuations totally unacceptable. Results are presented for a supersonic jet at Mach number 2.1.

  8. Propagation of sound

    DEFF Research Database (Denmark)

    Wahlberg, Magnus; Larsen, Ole Næsbye

    2017-01-01

    properties can be modified by sound absorption, refraction, and interference from multi paths caused by reflections.The path from the source to the receiver may be bent due to refraction. Besides geometrical attenuation, the ground effect and turbulence are the most important mechanisms to influence...... communication sounds for airborne acoustics and bottom and surface effects for underwater sounds. Refraction becomes very important close to shadow zones. For echolocation signals, geometric attenuation and sound absorption have the largest effects on the signals....

  9. Safety assessment plans for authorization and inspection of radiation sources

    International Nuclear Information System (INIS)

    2002-05-01

    The objective of this TECDOC is to enhance the efficacy, quality and efficiency of the whole regulatory process. It provides advice on good practice administrative procedures for the regulatory process for preparation of applications, granting of authorizations, inspection, and enforcement. It also provides information on the development and use of standard safety assessment plans for authorization and inspection. The plans are intended to be used in conjunction with more detailed advice related to specific practices. In this sense, this TECDOC provides advice on a systematic approach to evaluations of protection and safety while other IAEA Safety Guides assist the user to distinguish between the acceptable and the unacceptable. This TECDOC covers administrative advice to facilitate the regulatory process governing authorization and inspection. It also covers the use of standard assessment and inspection plans and provides simplified plans for the more common, well established uses of radiation sources in medicine and industry, i.e. sources for irradiation facilities, industrial radiography, well logging, industrial gauging, unsealed sources in industry, X ray diagnosis, nuclear medicine, teletherapy and brachytherapy

  10. Safety assessment plans for authorization and inspection of radiation sources

    International Nuclear Information System (INIS)

    1999-09-01

    The objective of this TECDOC is to enhance the efficacy, quality and efficiency of the whole regulatory process. It provides advice on good practice administrative procedures for the regulatory process for preparation of applications, granting of authorizations, inspection, and enforcement. It also provides information on the development and use of standard safety assessment plans for authorization and inspection. The plans are intended to be used in conjunction with more detailed advice related to specific practices. In this sense, this TECDOC provides advice on a systematic approach to evaluations of protection and safety while other IAEA Safety Guides assist the user to distinguish between the acceptable and the unacceptable. This TECDOC covers administrative advice to facilitate the regulatory process governing authorization and inspection. It also covers the use of standard assessment and inspection plans and provides simplified plans for the more common, well established uses of radiation sources in medicine and industry, i.e. sources for irradiation facilities, industrial radiography, well logging, industrial gauging, unsealed sources in industry, X ray diagnosis, nuclear medicine, teletherapy and brachytherapy

  11. Deconvolution for the localization of sound sources using a circular microphone array

    DEFF Research Database (Denmark)

    Tiana Roig, Elisabet; Jacobsen, Finn

    2013-01-01

    During the last decade, the aeroacoustic community has examined various methods based on deconvolution to improve the visualization of acoustic fields scanned with planar sparse arrays of microphones. These methods assume that the beamforming map in an observation plane can be approximated by a c......-negative least squares, and the Richardson-Lucy. This investigation examines the matter with computer simulations and measurements....... that the beamformer's point-spread function is shift-invariant. This makes it possible to apply computationally efficient deconvolution algorithms that consist of spectral procedures in the entire region of interest, such as the deconvolution approach for the mapping of the acoustic sources 2, the Fourier-based non...

  12. A review on the major sources of the interior sound vibration and riding comfort in vehicles

    Science.gov (United States)

    AlDhahebi, Adel Mohammed; Junoh, Ahmad Kadri; Ahmed, Amran

    2016-10-01

    Vehicle interior comfort is a crucial criteria that is considered by the perspective customer when purchasing a new vehicle. Meanwhile, automotive industries face the challenges for producing vehicles with better design criteria that meet the expectations of customers and eventually promote higher competitive advantages in areas of acoustic performance, cost effectiveness, product weight, and global competitive market. This review presents the major sources that influence the generation of noise and vibration in the interior part of the vehicles. It also demonstrates the relative methods that are used to assess the interior acoustics and vibration and further improve the riding comfort. This study is of a particular importance for acoustical researchers and automobile engineers, where it brings about suggestions and fundamentals that can contribute to acoustical comfort in vehicles.

  13. Research using synchrotron radiation at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Thomlinson, W.

    1982-01-01

    The National Synchrotron Light Source (NSLS) is now becoming operational with synchrotron radiation experiments beginning on the 700 MeV VUV electron storage ring. Commissioning of the 2.5 GeV x-ray storage ring has also begun with the experimental program expected to begin in 1983. The current status of the experimental program and instrumentation and the plans for future developments, will be discussed. Although some early results have been obtained on VUV beam lines no attempt will be made in this paper to describe them. Instead, an overview of the beam line characteristics will be given, with an indication of those already operational. In the oral presentation some initial experimental results will be discussed

  14. Device for forming the image of a radiation source

    International Nuclear Information System (INIS)

    Tosswill, C.H.

    1980-01-01

    An improvement can be made to the space resolution of systems providing the image of a radiation source by means of a slit collimator. In order to do so, a lateral movement of the collimator (with its detectors) is superimposed on the movement of the collimator, in a transversal direction in relation to the transmission direction through the collimator as well as in relation to the walls defining the slits. The total amplitude of the lateral movement is at least equal to the distance between centres of a slit and the following one. In the near field operating system, the lateral movement is a rectilinear movement perpendicular to the walls of the slits. In the distance field operating systems, it is an angular movement about an axis perpendicular to the direction of transmission through the slits [fr

  15. Tabulation of Fundamental Assembly Heat and Radiation Source Files

    International Nuclear Information System (INIS)

    T. deBues; J.C. Ryman

    2006-01-01

    The purpose of this calculation is to tabulate a set of computer files for use as input to the WPLOAD thermal loading software. These files contain details regarding heat and radiation from pressurized water reactor (PWR) assemblies and boiling water reactor (BWR) assemblies. The scope of this calculation is limited to rearranging and reducing the existing file information into a more streamlined set of tables for use as input to WPLOAD. The electronic source term files used as input to this calculation were generated from the output files of the SAS2H/ORIGIN-S sequence of the SCALE Version 4.3 modular code system, as documented in References 2.1.1 and 2.1.2, and are included in Attachment II

  16. Exposure to natural sources of radiation in Spain

    International Nuclear Information System (INIS)

    Quindos, L.S.; Fernandez, P.L.; Soto, J.

    1992-01-01

    Studies carried by us during last three years have produced a map of natural radiation for Spain. The map contains, by administrative region, the respective contributions of terrestrial gamma rays, both outdoors and indoors, cosmic rays and indoor radon. Terrestrial gamma rays have been measured outdoors 'in situ' in more than 1,000 locations. Data for indoor gamma rays were derived from the radioactivity content of more typical spanish building materials as also by 'in situ'measurements in approximately 100 houses. The cosmic ray component is calculated from latitude and altitude. Values for indoor radon exposure have been derived from a national survey and covering more than 2,000 individual measurements employing active and passive detectors. When account is taken of exposures elsewhere, the mean annual effective dose equivalent from these sources is evaluated. Doses from thoron decay products and internal exposure due to natural activity retained in the body from diet are not dealt with in this evaluation. (author)

  17. Notification and authorization for the use of radiation sources (supplement to IAEA Safety Standards Series No. GS-G-1.5)

    International Nuclear Information System (INIS)

    2010-10-01

    The achievement and maintenance of a high level of safety in the use of radiation sources depend on there being a sound legal and governmental infrastructure, including a national regulatory body with well-defined responsibilities and functions. These responsibilities and functions include establishing and implementing a system for notification and authorization for control over radiation sources, including a system for review and assessment of applications for authorization. The Safety Requirements publication entitled Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety establishes the requirements for legal and governmental infrastructure. The term 'infrastructure' refers to the underlying structure of systems and organizations. This includes requirements concerning the establishment of a regulatory body for radiation sources and the responsibilities and functions assigned to it. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or the BSS) establish basic requirements for protection against risks associated with exposure to ionizing radiation and for the safety of radiation sources. The application of the BSS is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities to for radiation protection and safety. This TECDOC provides practical guidance on the process for dealing with applications for authorization and accepting notifications to regulatory bodies. Examples of guidelines that may be used by persons required to notify or apply for authorization and of the regulatory body's review and assessment procedures are provided in the Appendices. The TECDOC is oriented towards national regulatory infrastructures concerned with protection and safety for radiation sources used in medicine, industry, agriculture, research and education

  18. Notification and authorization for the use of radiation sources (supplement to IAEA Safety Standards Series No. GS-G-1.5)

    International Nuclear Information System (INIS)

    2007-04-01

    The achievement and maintenance of a high level of safety in the use of radiation sources depend on there being a sound legal and governmental infrastructure, including a national regulatory body with well-defined responsibilities and functions. These responsibilities and functions include establishing and implementing a system for notification and authorization for control over radiation sources, including a system for review and assessment of applications for authorization. The Safety Requirements publication entitled Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety establishes the requirements for legal and governmental infrastructure. The term 'infrastructure' refers to the underlying structure of systems and organizations. This includes requirements concerning the establishment of a regulatory body for radiation sources and the responsibilities and functions assigned to it. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards or the BSS) establish basic requirements for protection against risks associated with exposure to ionizing radiation and for the safety of radiation sources. The application of the BSS is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities to for radiation protection and safety. This TECDOC provides practical guidance on the process for dealing with applications for authorization and accepting notifications to regulatory bodies. Examples of guidelines that may be used by persons required to notify or apply for authorization and of the regulatory body's review and assessment procedures are provided in the Appendices. The TECDOC is oriented towards national regulatory infrastructures concerned with protection and safety for radiation sources used in medicine, industry, agriculture, research and education

  19. A seafloor electromagnetic receiver for marine magnetotellurics and marine controlled-source electromagnetic sounding

    Science.gov (United States)

    Chen, Kai; Wei, Wen-Bo; Deng, Ming; Wu, Zhong-Liang; Yu, Gang

    2015-09-01

    In planning and executing marine controlled-source electromagnetic methods, seafloor electromagnetic receivers must overcome the problems of noise, clock drift, and power consumption. To design a receiver that performs well and overcomes the abovementioned problems, we performed forward modeling of the E-field abnormal response and established the receiver's characteristics. We describe the design optimization and the properties of each component, that is, low-noise induction coil sensor, low-noise Ag/AgCl electrode, low-noise chopper amplifier, digital temperature-compensated crystal oscillator module, acoustic telemetry modem, and burn wire system. Finally, we discuss the results of onshore and offshore field tests to show the effectiveness of the developed seafloor electromagnetic receiver and its performance: typical E-field noise of 0.12 nV/m/rt(Hz) at 0.5 Hz, dynamic range higher than 120 dB, clock drift lower than 1 ms/day, and continuous operation of at least 21 days.

  20. Ionizing radiations used in medical diagnostics as a source of radiation exposure of the Bulgarian population

    International Nuclear Information System (INIS)

    Ingilizova, K.; Vasilev, G.

    1998-01-01

    X-ray and radionuclide application in medical diagnosing is the major sources of Bulgarian population exposure to ionizing radiations exceeding the radiation background. The number of X-ray examination on a nationwide scale shows an increase from 1600 thousand annually in 1950 to 10300 thousand in 1980 and decreases to about 4700 thousand annually for the period 1992-1993. The frequency for the above mentioned time intervals varies in the range 0.22 to 1.17 examinations per capita annually and decreases to 0.56. The roentgenoscopy to roentgenography ratio varies from 2.5:1 to 0.9:1 (1975) and increases to 2.0:1 (1993). The number of radioisotope examinations increased from 34 thousand in 1970 to 170 thousand annually in 1985 and decreased to about thousand annually in 1992-1993 with a number of studies per capita varying from 0.004 to 0.020 and decreasing to 0.010. In 1993 the annual collective effective dose due to X-ray diagnostics amounts to about 7000 man-Sv/a which exceeds the radiation background exposure by 76%. Radioisotope diagnostics in the period reviewed accounted for nearly 700 man-Sv/a with an exposure exceeding the radiation background by 7.7%. The major problems relating to patient protection and benefit/risk ratio improvement are discussed. (author)

  1. Using ILD or ITD Cues for Sound Source Localization and Speech Understanding in a Complex Listening Environment by Listeners with Bilateral and with Hearing-Preservation Cochlear Implants

    Science.gov (United States)

    Loiselle, Louise H.; Dorman, Michael F.; Yost, William A.; Cook, Sarah J.; Gifford, Rene H.

    2016-01-01

    Purpose: To assess the role of interaural time differences and interaural level differences in (a) sound-source localization, and (b) speech understanding in a cocktail party listening environment for listeners with bilateral cochlear implants (CIs) and for listeners with hearing-preservation CIs. Methods: Eleven bilateral listeners with MED-EL…

  2. Sources of Nutrients to Nearshore Areas of a Eutrophic Estuary: Implications for Nutrient-Enhanced Acidification in Puget Sound

    Science.gov (United States)

    Pacella, S. R.

    2016-02-01

    Ocean acidification has recently been highlighted as a major stressor for coastal organisms. Further work is needed to assess the role of anthropogenic nutrient additions in eutrophied systems on local biological processes, and how this interacts with CO2 emission-driven acidification. This study sought to distinguish changes in pH caused by natural versus anthropogenically affected processes. We quantified the variability in water column pH attributable to primary production and respiration fueled by anthropogenically derived nitrogen in a shallow nearshore area. Two study sites were located in shallow subtidal areas of the Snohomish River estuary, a eutrophic system located in central Puget Sound, Washington. These sites were chosen due to the presence of heavy agricultural activity, urbanized areas with associated waste water treatment, as well as influence from deep, high CO2 marine waters transported through the Strait of Juan de Fuca and upwelled into the area during spring and summer. Data was collected from July-December 2015 utilizing continuous moorings and discrete water column sampling. Analysis of stable isotopes, δ15N, δ18O-NO3, δ15N-NH4, was used to estimate the relative contributions of anthropogenic versus upwelled marine nitrogen sources. Continuous monitoring of pH, dissolved oxygen, temperature, and salinity was conducted at both study sites to link changes in nutrient source and availability with changes in pH. We predicted that isotope data would indicate greater contributions of nitrogen from agriculture and wastewater rather than upwelling in the shallow, nearshore study sites. This study seeks to distinguish the relative magnitude of pH change stimulated by anthropogenic versus natural sources of nitrogen to inform public policy decisions in critically important nearshore ecosystems.

  3. Radiation protection and safety of radiation sources international basic safety standards

    CERN Document Server

    International Atomic Energy Agency. Vienna

    2014-01-01

    The Board of Governors of the IAEA first approved Basic Safety Standards in June 1962; they were published by the IAEA as IAEA Safety Series No. 9. A revised edition was issued in 1967. A third revision was published by the IAEA as the 1982 Edition of IAEA Safety Series No. 9 ; this edition was jointly sponsored by the IAEA, ILO, OECD/NEA and the WHO. The next edition was International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, published by the IAEA as IAEA Safety Series No. 115 in February 1996, and jointly sponsored by the FAO, IAEA, ILO, OECD/NEA, PAHO and the WHO.

  4. Radiation accident caused by an iridium-192 radiographic source

    International Nuclear Information System (INIS)

    Kumatori, T.; Hirashima, K.; Ishihara, T.; Kurisu, A.; Sugiyama, H.; Hashizume, T.

    1977-01-01

    Owing to the carelessness of a radiographer, six construction workers, aged from twenty to thirty, were accidentally exposed to gamma rays of a 192 Ir source for a non-destructive radiography. These exposed persons were not directly involved with radiographic work. One case revealed severe leucopenia and thrombopenia accompanied by moderate anaemia. In three cases including the case considered, skin lesions were observed on hands and hips, arising from close contact with a 192 Ir rod. The effects to the gonads consisted of impaired spermatogenesis in all cases and elevation of follicle-stimulating hormone in the sera of four cases. The ratio of one metabolite to another seemed to be more indicative of the injuries than the level of any given metabolite itself. In the physical estimate of the dose, the thermoluminescence intensity of rubies in the wrist watches of the exposed persons was measured, which was useful for the determination of the location of the source. The mean whole-body absorbed doses ranged from 10 to 133 rads. Local radiation doses were approximately 3000 to 9000 rads to the skin and 175 rads to the gonads of one case, respectively. The biological dose estimates were made by using the dose-response relations for 60 Co gamma rays and for Linac X-rays on the basis of the yields of dicentrics and rings. The doses were in the range of about 10 to 150 rads. Skin lesions and chromosome aberrations are still observed. (author)

  5. Regulation for oil wells logging using ionizing radiation sources. A draft

    International Nuclear Information System (INIS)

    Hidrowoh, Jacob

    2000-01-01

    A project to regulate logging activities using ionizing radiation sources in oil wells in Ecuador is proposed. Its development is based on basic concepts of energy, radiation protection and characteristics of oil exploitation in Ecuador

  6. Photo-acoustic and video-acoustic methods for sensing distant sound sources

    Science.gov (United States)

    Slater, Dan; Kozacik, Stephen; Kelmelis, Eric

    2017-05-01

    , doing so requires overcoming significant limitations typically including much lower sample rates, reduced sensitivity and dynamic range, more expensive video hardware, and the need for sophisticated video processing. The ATCOM real time image processing software environment provides many of the needed capabilities for researching video-acoustic signal extraction. ATCOM currently is a powerful tool for the visual enhancement of atmospheric turbulence distorted telescopic views. In order to explore the potential of acoustic signal recovery from video imagery we modified ATCOM to extract audio waveforms from the same telescopic video sources. In this paper, we demonstrate and compare both readout techniques for several aerospace test scenarios to better show where each has advantages.

  7. Radiation doses from radiation sources of neutrons and photons by different computer calculation

    International Nuclear Information System (INIS)

    Siciliano, F.; Lippolis, G.; Bruno, S.G.

    1995-12-01

    In the present paper the calculation technique aspects of dose rate from neutron and photon radiation sources are covered with reference both to the basic theoretical modeling of the MERCURE-4, XSDRNPM-S and MCNP-3A codes and from practical point of view performing safety analyses of irradiation risk of two transportation casks. The input data set of these calculations -regarding the CEN 10/200 HLW container and dry PWR spent fuel assemblies shipping cask- is frequently commented as for as connecting points of input data and understanding theoric background are concerned

  8. Cognitive and linguistic sources of variance in 2-year-olds’ speech-sound discrimination: a preliminary investigation.

    Science.gov (United States)

    Lalonde, Kaylah; Holt, Rachael Frush

    2014-02-01

    This preliminary investigation explored potential cognitive and linguistic sources of variance in 2-year-olds’ speech-sound discrimination by using the toddler change/ no-change procedure and examined whether modifications would result in a procedure that can be used consistently with younger 2-year-olds. Twenty typically developing 2-year-olds completed the newly modified toddler change/no-change procedure. Behavioral tests and parent report questionnaires were used to measure several cognitive and linguistic constructs. Stepwise linear regression was used to relate discrimination sensitivity to the cognitive and linguistic measures. In addition, discrimination results from the current experiment were compared with those from 2-year-old children tested in a previous experiment. Receptive vocabulary and working memory explained 56.6% of variance in discrimination performance. Performance was not different on the modified toddler change/no-change procedure used in the current experiment from in a previous investigation, which used the original version of the procedure. The relationship between speech discrimination and receptive vocabulary and working memory provides further evidence that the procedure is sensitive to the strength of perceptual representations. The role for working memory might also suggest that there are specific subject-related, nonsensory factors limiting the applicability of the procedure to children who have not reached the necessary levels of cognitive and linguistic development.

  9. Contribution of a 3D ray tracing model in a complex medium to the localization of infra-sound sources

    International Nuclear Information System (INIS)

    Mialle, Pierrick

    2007-01-01

    Localisation of infra-sound sources is a difficult task due to large propagation distances at stake and because of the atmospheric complexity. In order to resolve this problem, one can seek as many necessary information as the comprehension of wave propagation, the role and influence of the atmosphere and its spatio-temporal variations, the knowledge of sources and detection parameters, but also the configuration of the stations and their global spreading. Two methods based on the construction of propagation tables depending on station, date and time are introduced. Those tables require a long range propagation tool to simulate the propagation through a complex medium, which are carried out by WASP-3D Sph a 3D paraxial ray tracing based-theory tool integrating both amplitude estimation and horizontal wind fields in space and time. Tables are centered on the receptor. They describe spatial variations of the main observation parameters and offer a snapshot of the atmospheric propagation depending on the range for every simulated phase. For each path, celerity, azimuth deviation, attenuation and return altitude are predicted and allow building the tables. The latter help to identify detected phases and are integrated in an accurate localization procedure. The procedure is tested on three case study, such as the explosion of gas-pipeline in Belgium 2004 near Ghislenghien, the explosion of a military facility in 2007 in Novaky, Slovakia and the explosion of the Buncefield oil depot in 2005 in the United Kingdom, where event specificities, propagation parameters and used configurations are introduced. The accuracy and optimization of the localization are discussed. A validation study is presented regarding International Monitoring System stations along a meridian - I18DK (Greenland, Denmark), I51UK (Bermuda, United Kingdom), I25FR (Guyane, France), I08BO (La Paz, Bolivia), I01AR (Paso Flores, Argentina), I02AR (Ushuaia, Argentina), I54US (Antarctica, U.S.A.) - to

  10. Transition radiation in metal-metal multilayer nanostructures as a medical source of hard x-ray radiation

    International Nuclear Information System (INIS)

    Pokrovsky, A. L.; Kaplan, A. E.; Shkolnikov, P. L.

    2006-01-01

    We show that a periodic metal-metal multilayer nanostructure can serve as an efficient source of hard x-ray transition radiation. Our research effort is aimed at developing an x-ray source for medical applications, which is based on using low-energy relativistic electrons. The approach toward choosing radiator-spacer couples for the generation of hard x-ray resonant transition radiation by few-MeV electrons traversing solid multilayer structures for the energies of interest to medicine (30-50 keV) changes dramatically compared with that for soft x-ray radiation. We show that one of the main factors in achieving the required resonant line is the absence of the contrast of the refractive indices between the spacer and the radiator at the far wings of the radiation line; for that purpose, the optimal spacer, as a rule, should have a higher atomic number than the radiator. Having experimental goals in mind, we have considered also the unwanted effects due to bremsstrahlung radiation, absorption and scattering of radiated photons, detector-related issues, and inhibited coherence of transition radiation due to random deviation of spacing between the layers. Choosing as a model example a Mo-Ag radiator-spacer pair of materials, we demonstrate that the x-ray transition radiation line can be well resolved with the use of spatial and frequency filtering

  11. Non-Ionizing Radiation - sources, exposure and health effects

    International Nuclear Information System (INIS)

    Hietanen, M.

    2003-01-01

    Non-ionizing radiation contains the electromagnetic wavelengths from ultraviolet (UV) radiation to static electric and magnetic fields. Optical radiation consists of UV, visible and infrared (IR) radiation while EM fields include static, extremely low (ELF), low frequency (LF) and radiofrequency (RF) fields. The principal scientific organization on non-ionizing radiation is the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The main activity of ICNIRP is to provide guidance on safe exposure and protection of workers and members of the public by issuing statements and recommendations. (orig.)

  12. Cherenkov Radiation from a Pseudospark-sourced Electron Beam

    International Nuclear Information System (INIS)

    Phelps, A.D.R.; Yin, H.; Cross, A.W.; He, W.; Ronald, K.

    2003-01-01

    Electron beam generation from a multi-gap pseudospark discharge was investigated. A pseudospark-sourced electron beam has two phases, an initial hollow cathode phase (HCP) beam followed by a conductive phase (CP) beam. The beam brightness was measured by a field-free collimator to be 109 and 1011 Am-2rad-2 for the hollow cathode phase (HCP) beam and the conductive phase (CP) beam respectively. The initial HCP beam from an eight-gap pseudospark discharge was applied in a Cherenkov interaction between the electron beam and the TM01 mode of a 60-cm long alumina-lined waveguide. It was found experimentally that significant microwave radiation was generated only when the dielectric was present in the interaction space. If there was no dielectric in the cylindrical waveguide, then a very small background microwave output was detected even when the guide B-field was absent. This demonstrated, in conjunction with the observation that the microwave output signal was independent of the guide magnetic field over the range 0.13 to 0.26 T, that the radiation from the experiment was due to the Cherenkov interaction mechanism. In addition, two components of the microwave pulse were observed corresponding to the two energy components of the electron beam during the pseudospark discharge breakdown. These results demonstrated that the microwave radiation was generated by Cherenkov amplification of the broadband emission from the pseudospark discharge itself. A background signal level of around 100 W was measured in the frequency range 20 - 50 GHz with a percentage of (2.7 ± 0.6)% in the frequency range 25.5 - 28.6 GHz, when the dielectric lining was removed from the maser. The frequency of the microwave output after the Cherenkov maser interaction was measured to be mainly around 25.5 GHz and the dominating mode was identified as being TM01. The duration of the microwave pulse was approximately 80 ns, with a peak power of around 2 ± 0.2 kW. The gain of this amplifier was measured

  13. Novel particle and radiation sources and advanced materials

    Energy Technology Data Exchange (ETDEWEB)

    Mako, Frederick [FM Technologies, Inc. and Electron Technologies, Inc. (United States)

    2016-03-25

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and “green” klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  14. Novel particle and radiation sources and advanced materials

    International Nuclear Information System (INIS)

    Mako, Frederick

    2016-01-01

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and “green” klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  15. Novel particle and radiation sources and advanced materials

    Science.gov (United States)

    Mako, Frederick

    2016-03-01

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and "green" klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  16. Protection during work with ionizing radiation sources; Ochrana pri praci se zdroji ionizujiciho zareni

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The publication has been set up as a textbook for training courses dealing with health protection during work with ionizing radiation, designed for supervisory staff and persons directly responsible for activities which involve the handling of ionizing radiation sources. The book consists of a preface and the following chapters: (1) Fundamentals of ionizing radiation physics; (2) Quantities and units used in ionizing radiation protection; (3) Principles of ionizing radiation dosimetry; (4) Biological effects of ionizing radiation; (5) An overview of sources of public irradiation; (6) Principles and methods of health protection against ionizing radiation; (7) Examples of technical applications of sources of ionizing radiation; (8) Personnel and working environment monitoring; (9) Documentation maintained at sites with ionizing radiation sources; (10) Methods of personnel protection against external irradiation and internal radionuclide contamination; (11) Radiation incidents and accidents; (12) Health care of personnel exposed to the ionizing radiation risk; (12) Additional radiation protection requirements in handling radioactive substances other than sealed sources; (13) Measurement and metrology. (P.A.).

  17. Efficient approximation of the Struve functions Hn occurring in the calculation of sound radiation quantities.

    Science.gov (United States)

    Aarts, Ronald M; Janssen, Augustus J E M

    2016-12-01

    The Struve functions H n (z), n=0, 1, ...  are approximated in a simple, accurate form that is valid for all z≥0. The authors previously treated the case n = 1 that arises in impedance calculations for the rigid-piston circular radiator mounted in an infinite planar baffle [Aarts and Janssen, J. Acoust. Soc. Am. 113, 2635-2637 (2003)]. The more general Struve functions occur when other acoustical quantities and/or non-rigid pistons are considered. The key step in the paper just cited is to express H 1 (z) as (2/π)-J 0 (z)+(2/π) I(z), where J 0 is the Bessel function of order zero and the first kind and I(z) is the Fourier cosine transform of [(1-t)/(1+t)] 1/2 , 0≤t≤1. The square-root function is optimally approximated by a linear function ĉt+d̂, 0≤t≤1, and the resulting approximated Fourier integral is readily computed explicitly in terms of sin z/z and (1-cos z)/z 2 . The same approach has been used by Maurel, Pagneux, Barra, and Lund [Phys. Rev. B 75, 224112 (2007)] to approximate H 0 (z) for all z≥0. In the present paper, the square-root function is optimally approximated by a piecewise linear function consisting of two linear functions supported by [0,t̂ 0 ] and [t̂ 0 ,1] with t̂ 0 the optimal take-over point. It is shown that the optimal two-piece linear function is actually continuous at the take-over point, causing a reduction of the additional complexity in the resulting approximations of H 0 and H 1 . Furthermore, this allows analytic computation of the optimal two-piece linear function. By using the two-piece instead of the one-piece linear approximation, the root mean square approximation error is reduced by roughly a factor of 3 while the maximum approximation error is reduced by a factor of 4.5 for H 0 and of 2.6 for H 1 . Recursion relations satisfied by Struve functions, initialized with the approximations of H 0 and H 1 , yield approximations for higher order Struve functions.

  18. Diffraction-enhanced imaging at the UK synchrotron radiation source

    International Nuclear Information System (INIS)

    Ibison, M.; Cheung, K.C.; Siu, K.; Hall, C.J.; Lewis, R.A.; Hufton, A.; Wilkinson, S.J.; Rogers, K.D.; Round, A.

    2005-01-01

    The Diffraction-Enhanced Imaging (DEI) system, which shares access to Beamline 7.6 on the Daresbury Synchrotron Radiation Source (SRS), is now in its third year of existence. The system was developed under a European Commission grant PHase Analyser SYstem (PHASY), won during the Fourth Framework. Typical applications continue to be the imaging of small biological specimens, using a beam of 12-17 keV after monochromation and up to 40 mm in width and 1-2 mm in height, although it is planned to investigate other materials as opportunity permits and time becomes available for more routine scientific use. Recent improvements have been made to the optical alignment procedure for setting up the station before imaging: a small laser device can now be set up to send a beam down the X-ray path through the four crystals, and a small photodiode, which has much better signal-to-noise characteristics than the ion chamber normally used for alignment, has been trailed successfully. A 3-D tomographic reconstruction capability has recently been developed and tested for DEI projection image sets, and will be applied to future imaging work on the SRS, in conjunction with volume visualization software. The next generation of DEI system, planned to operate at up to 60 keV on an SRS wiggler station, is in its design stage; it will feature much improved mechanics and mountings, especially for angular control, and a simplified alignment procedure to facilitate the necessary sharing of the SRS station

  19. Disk shaped radiation sources for education purposes made of chemical fertilizer

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    A method for fabricating a disk-shaped radiation source from material containing natural radioisotopes was developed. In this compression and formation method, a certain amount of powdered material is placed in a stainless steel formwork and compressed to form a solid disk. Using this method, educational radiation sources were fabricated using commercially available chemical fertilizers that naturally contain the radionuclide, 40 K, which emits either beta or gamma rays, at each disintegration. The compression and formation method was evaluated by inspecting eleven radiation sources thus fabricated. Then the suitability of the fertilizer radiation source as an education aid was evaluated. The results showed that the method could be used to fabricate radiation sources without the need for learning special skills or techniques. It was also found that the potassium fertilizer radiation source could be used to demonstrate that the inverse-square law can be applied to the distance between the radiation source and detector, and that an exponential relationship can be seen between the shielding effectiveness and the total thickness of the shielding materials. It is concluded that a natural fertilizer radiation source is an appropriate aid for demonstrating the characteristics of radiation. (author)

  20. Sound algorithms

    OpenAIRE

    De Götzen , Amalia; Mion , Luca; Tache , Olivier

    2007-01-01

    International audience; We call sound algorithms the categories of algorithms that deal with digital sound signal. Sound algorithms appeared in the very infancy of computer. Sound algorithms present strong specificities that are the consequence of two dual considerations: the properties of the digital sound signal itself and its uses, and the properties of auditory perception.